##### SUMMARY
`ansible-galaxy collection install` currently requires the user to specify an install path using the `-p` option. Galaxy currently generates and displays the CLI command for installing a collection. There is no way for Galaxy to determine a value for `-p`, and hard coding a default value into Galaxy makes no sense.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
`ansible-galaxy`

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```
ansible 2.10.0.dev0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/Users/chouseknecht/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/chouseknecht/projects/ansible/lib/ansible
  executable location = /Users/chouseknecht/.pyenv/versions/venv27/bin/ansible
  python version = 2.7.14 (default, Nov 14 2017, 23:24:24) [GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.38)]
```

elif not force:
                raise AnsibleError("- the directory %s already exists. "
                                   "You can use --force to re-initialize this directory,\n"
                                   "however it will reset any main.yml files that may have\n"
                                   "been modified there already." % to_native(obj_path))
        if obj_skeleton is not None:
            own_skeleton = False
            skeleton_ignore_expressions = C.GALAXY_ROLE_SKELETON_IGNORE
        else:
            own_skeleton = True
            obj_skeleton = self.galaxy.default_role_skeleton_path
            skeleton_ignore_expressions = ['^.*/.git_keep$']
        obj_skeleton = os.path.expanduser(obj_skeleton)
        skeleton_ignore_re = [re.compile(x) for x in skeleton_ignore_expressions]
        if not os.path.exists(obj_skeleton):
            raise AnsibleError("- the skeleton path '{0}' does not exist, cannot init {1}".format(
                to_native(obj_skeleton), galaxy_type)
            )
        template_env = Environment(loader=FileSystemLoader(obj_skeleton))
        
        if not os.path.exists(b_obj_path):
            os.makedirs(b_obj_path)
        for root, dirs, files in os.walk(obj_skeleton, topdown=True):
            rel_root = os.path.relpath(root, obj_skeleton)
            rel_dirs = rel_root.split(os.sep)
            rel_root_dir = rel_dirs[0]
            if galaxy_type == 'collection':
                
                in_templates_dir = rel_root_dir in ['playbooks', 'roles'] and 'templates' in rel_dirs
            else: