##### SUMMARY
The command `ansible-galaxy collection list` should not _error_ when parsing a particular collection, because this prevents displaying a list of _all other_ collections.

This happens when simply using the source checkout of `community.vmware`.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
lib/ansible/cli/galaxy.py

##### ANSIBLE VERSION
```paste below
[WARNING]: You are running the development version of Ansible. You should only run Ansible from "devel" if you are modifying the Ansible engine, or trying out features under
development. This is a rapidly changing source of code and can become unstable at any point.
ansible 2.11.0.dev0
  config file = None
  configured module search path = ['/Users/alancoding/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/alancoding/Documents/repos/ansible/lib/ansible
  executable location = /Users/alancoding/.virtualenvs/awx_collection/bin/ansible
  python version = 3.7.7 (default, Mar 10 2020, 15:43:03) [Clang 11.0.0 (clang-1100.0.33.17)]
```

86606d3ca707e8836d2b956694bb55d3ae282aee

##### CONFIGURATION
```paste below
ansible-config dump --only-changed
```

(collection path modification in steps)

##### OS / ENVIRONMENT
N/A


##### STEPS TO REPRODUCE

```
base_dir=awx/plugins/collections/ansible_collections
mkdir -p $base_dir/community
git clone https://github.com/ansible-collections/vmware.git $base_dir/community/vmware
```

on the revision of this collection `2b277d44fa664443be679c13a66bdf2c60a75093`

```
ANSIBLE_COLLECTIONS_PATHS=awx/plugins/collections ansible-galaxy collection list -vvv
```

##### EXPECTED RESULTS
lists all the collections in the folder `awx/plugins/collections`, and gives `*` for the version of `community.vmware` because I don't expect that maintainers are necessarily including the version in their `galaxy.yml`.

In this particular case, the file is:

```yaml
---
namespace: community
name: vmware
# the version key is generated during the release by Zuul
# https://github.com/ansible-network/releases/tree/master/ansible_releases/cmd
# A script based on https://pypi.org/project/pbr/ will generate the version
# key. The version value depends on the tag or the last git tag.
readme: README.md
authors:
  - Ansible (https://github.com/ansible)
description:
license_file: LICENSE
tags:
  - cloud
  - vmware
  - virtualization
dependencies: {}
```

Of course they're doing this, they're using tags and CI in their release process. As an example of a collection with _no_ `galaxy.yml`

```
# /Users/alancoding/.ansible/collections/ansible_collections
Collection             Version    
---------------------- -----------
chrismeyersfsu.hax0r   *          
```

It should show the same thing for the vmware collection source checkout

##### ACTUAL RESULTS

```
ANSIBLE_COLLECTIONS_PATHS=awx/plugins/collections ansible-galaxy collection list -vvv
[WARNING]: You are running the development version of Ansible. You should only run Ansible from "devel" if you are modifying the Ansible engine, or trying out features under
development. This is a rapidly changing source of code and can become unstable at any point.
ansible-galaxy 2.11.0.dev0
  config file = None
  configured module search path = ['/Users/alancoding/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/alancoding/Documents/repos/ansible/lib/ansible
  executable location = /Users/alancoding/.virtualenvs/awx_collection/bin/ansible-galaxy
  python version = 3.7.7 (default, Mar 10 2020, 15:43:03) [Clang 11.0.0 (clang-1100.0.33.17)]
No config file found; using defaults
[DEPRECATION WARNING]: ANSIBLE_COLLECTIONS_PATHS option, all PATH-type options are singular PATH , use the "ANSIBLE_COLLECTIONS_PATH" environment variable instead. This feature 
will be removed in version 2.14. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
Searching /Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections for collections
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/alancoding-cloud-0.0.1.tar.gz' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/alancoding-cloud-0.0.3.tar.gz' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/.tox' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/plugins/inventory/__pycache__' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/build_artifact/openstack-cloud-0.0.1-dev82.tar.gz' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/alancoding-cloud-0.0.2.tar.gz' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud/galaxy.yml' for collection build
Found installed collection alancoding.cloud:0.0.3 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/openstack/cloud'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/amazon/aws/plugins/doc_fragments/__pycache__' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/amazon/aws/plugins/inventory/__pycache__' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/amazon/aws/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/amazon/aws/galaxy.yml' for collection build
Found installed collection amazon.aws:0.1.0 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/amazon/aws'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/azure/azcollection/plugins/doc_fragments/__pycache__' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/azure/azcollection/plugins/inventory/__pycache__' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/azure/azcollection/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/azure/azcollection/galaxy.yml' for collection build
Found installed collection azure.azcollection:0.1.3 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/azure/azcollection'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/google/cloud/plugins/inventory/__pycache__' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/google/cloud/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/google/cloud/galaxy.yml' for collection build
Found installed collection google.cloud:0.0.9 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/google/cloud'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/ansible/posix/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/ansible/posix/galaxy.yml' for collection build
Found installed collection ansible.posix:0.1.1 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/ansible/posix'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/ansible/amazon/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/ansible/amazon/galaxy.yml' for collection build
Found installed collection ansible.amazon:0.1.0 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/ansible/amazon'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/theforeman/foreman/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/theforeman/foreman/galaxy.yml' for collection build
Found installed collection theforeman.foreman:0.7.0 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/theforeman/foreman'
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/community/general/.git' for collection build
Skipping '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/community/general/galaxy.yml' for collection build
Found installed collection community.general:0.1.1 at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/community/general'
ERROR! The collection galaxy.yml at '/Users/alancoding/Documents/tower/awx/plugins/collections/ansible_collections/community/vmware/galaxy.yml' is missing the following mandatory keys: version
```

It's bad that the command terminates so fragilely. This also just doesn't jive with the common, published, policies of first-class collections.

It's also bad that it won't give a traceback for the error that happened.

FYI to @Akasurde (I'd expect no change in vmware collection) @jborean93 (most likely expect change in CLI error handling)

def get_manifest_info(namespace='ansible_namespace', name='collection', version='0.1.0'):
        return {
            "collection_info": {
                "namespace": namespace,
                "name": name,
                "version": version,
                "authors": [
                    "shertel"
                ],
                "readme": "README.md",
                "tags": [
                    "test",
                    "collection"
                ],
                "description": "Test",
                "license": [
                    "MIT"
                ],
                "license_file": None,
                "dependencies": {},
                "repository": "https://github.com/{0}/{1}".format(namespace, name),
                "documentation": None,
                "homepage": None,
                "issues": None
            },
            "file_manifest_file": {
                "name": "FILES.json",
                "ftype": "file",
                "chksum_type": "sha256",
                "chksum_sha256": "files_manifest_checksum",