Don't connect to Conduit in `arc feature name`

Summary: There's no need for having an Internet connection in creating a branch.

Test Plan:
  $ arc feature name # with disabled Internet
  $ arc feature
  [cURL/6] (https://secure.phabricator.com/api/conduit.connect)

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5430