'Invite the user to join this team.
This returns a dictionary like so::
{\'state\': \'pending\', \'url\': \'https://api.github.com/teams/...\'}
:param str username: (required), user to invite to join this team.
:returns: dictionary'

@requires_auth
def invite(self, username):

    url = self._build_url(u'memberships', username, base_url=self._api)
    return self._json(self._put(url), 200)
