Improve wording on the VM decorators.
Add form to apply to be a ``Hub`` guardian.

https://github.com/madewithbytes/us_ignite/issues/94

The form validates the minimum fields required to
apply.
Add utilities to generate request doubles.

The new ``get_request`` function is a helper used to generate
request doubles the first argument is the ``method``, an
optional user can be attached to the request.
Update tests to use the utilities to generate mock users.