##### SUMMARY
Environment variables in plugin do not match Tower credential injector

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
lib/ansible/plugins/inventory/vmware_vm_inventory.py

##### ANSIBLE VERSION
```
ansible 2.8.0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /bin/ansible
  python version = 2.7.5 (default, May 20 2019, 12:21:26) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]
```
##### CONFIGURATION
```paste below

```

##### OS / ENVIRONMENT
Red Hat Enterprise Linux Server release 7.5

##### STEPS TO REPRODUCE
use vmware inventory plugin with vCenter credential in Ansible Tower
```yaml
---
plugin: vmware_vm_inventory
validate_certs: False
```


##### EXPECTED RESULTS
inventory should be parsed

##### ACTUAL RESULTS
```paste below
 [WARNING]:  * Failed to parse
/var/lib/awx/projects/_16__ansible_inventory/tests/vmware_vm_inventory.yaml
with auto plugin: No setting was provided for required configuration
plugin_type: inventory plugin: vmware_vm_inventory setting: username
```

password: Esxi@123$%
    validate_certs: False
    with_tags: False
    properties:
    - 'name'
    - 'guest.ipAddress'
'''
import ssl
import atexit
from ansible.errors import AnsibleError, AnsibleParserError
try:
    
    import requests
    HAS_REQUESTS = True
except ImportError:
    HAS_REQUESTS = False
try:
    from pyVim import connect
    from pyVmomi import vim, vmodl
    HAS_PYVMOMI = True
except ImportError:
    HAS_PYVMOMI = False
try:
    from com.vmware.vapi.std_client import DynamicID
    from vmware.vapi.vsphere.client import create_vsphere_client
    HAS_VSPHERE = True
except ImportError:
    HAS_VSPHERE = False
from ansible.plugins.inventory import BaseInventoryPlugin, Cacheable
class BaseVMwareInventory: