<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
`ansible-galaxy collection install ...` will create a file to save the galaxy token in `~/.ansible_galaxy`. This causes problems when the users home dir isn't writeable and potential problems in a multi-tenant shared-user environment.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
ansible-galaxy collection

##### ADDITIONAL INFORMATION
I would like a knob to be able to tell `ansible-galaxy` not to create that file or a knob to specify the directory where the file can be created. Below is the traceback I get when my home dir doesn't allow write access.

##### Steps to recreate
`HOME=/ ansible-galaxy -vvv collection install chrismeyersfsu.tower_modules -p /tmp/here`

``` 
ansible-galaxy 2.9.0.dev0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /usr/bin/ansible-galaxy
  python version = 2.7.5 (default, Jun 20 2019, 20:27:34) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]
Using /etc/ansible/ansible.cfg as config file
ERROR! Unexpected Exception, this is probably a bug: [Errno 13] Permission denied: '//.ansible_galaxy'
the full traceback was:

Traceback (most recent call last):
  File "/usr/bin/ansible-galaxy", line 111, in <module>
    exit_code = cli.run()
  File "/usr/lib/python2.7/site-packages/ansible/cli/galaxy.py", line 267, in run
    self.api = GalaxyAPI(self.galaxy)
  File "/usr/lib/python2.7/site-packages/ansible/galaxy/api.py", line 65, in __init__
    self.token = GalaxyToken()
  File "/usr/lib/python2.7/site-packages/ansible/galaxy/token.py", line 39, in __init__
    self.config = yaml.safe_load(self.__open_config_for_read())
  File "/usr/lib/python2.7/site-packages/ansible/galaxy/token.py", line 48, in __open_config_for_read
    f = open(self.file, 'w')
IOError: [Errno 13] Permission denied: '//.ansible_galaxy'
```

''' Class to storing and retrieving token in ~/.ansible_galaxy '''
    def __init__(self):
        self.file = os.path.expanduser("~") + '/.ansible_galaxy'
        self.config = yaml.safe_load(self.__open_config_for_read())
        if not self.config:
            self.config = {}
    def __open_config_for_read(self):
        if os.path.isfile(self.file):
            display.vvv('Opened %s' % self.file)
            return open(self.file, 'r')
        
        f = open(self.file, 'w')
        f.close()
        os.chmod(self.file, S_IRUSR | S_IWUSR)  
        display.vvv('Created %s' % self.file)
        return open(self.file, 'r')
    def set(self, token):
        self.config['token'] = token
        self.save()
    def get(self):
        return self.config.get('token', None)
    def save(self):
        with open(self.file, 'w') as f:
            yaml.safe_dump(self.config, f, default_flow_style=False)