Update tests and Base.yml to auto-approve the default client, fixes T943

Summary: See T904.

Test Plan:
```
bin/behat --config application/tests/behat.yml -f progress application/tests/features/api.oauth.feature
```

Reviewers: rjmackay, aMoniker

Reviewed By: aMoniker

Subscribers: vladimir, srutto

Maniphest Tasks: T943

Differential Revision: https://phabricator.ushahidi.com/D453