docs: def add_key(self):
          "Add ssh key to gitlab if necessary"
          try:
              with open(self.args.ssh_public_key) as f:
                  public_key = f.read().strip()
          except:
              log.debug("No key found in {}".format(self.args.ssh_public_key))
              return None
          g = self.gitlab
          url = g['url'] + "/user/keys"
          query = {'private_token': g['token']}
          keys = requests.get(url, params=query).json()
          log.debug("looking for '" + public_key + "' in " + str(keys))
          if (list(filter(lambda key: key['key'] == public_key, keys))):
              log.debug(self.args.ssh_public_key + " already exists")
              return None
          else:
              name = 'github2gitlab'
              log.info("add " + name + " ssh public key from " +
                       self.args.ssh_public_key)
              query['title'] = name
              query['key'] = public_key
              result = requests.post(url, query)
              if result.status_code != requests.codes.created:
                  log.warn('Key {} already in GitLab. '
                           'Possible under a different user. Skipping...'
                           .format(self.args.ssh_public_key))
              return public_key