This includes two new tests in the integration test script to check that
boulder gets the correct code. The encoding is specified in RFC5280
5.3.1. The codes that boulder will accept are a subset of that,
specified in `boulder.revocation.reasons.go`.
* Output status for `revoke` operation. Fixes#2819.
- Added method to `certbot.display.ops` to output confirmation of `revoke`.
- Wrapped call to `acme.client.Client.revoke` in a try to statement to
handle possible error.
- Added test for `main.revoke`.
* Added test for failure of certificate revocation.
Moved creation of mocks into RevokeTest setup function.
Stopped mocks in RevokeTest teardown function.
* Fixed lint errors.
* Do not call `unittest.TestCase.assertRaises` as a context manager (to work with py26).
* Fixed spelling error in successful revocation notification.
Added test for the notification.