In order to be fully independent, REST tests should not depend on Tuleap internal API.
One of the objectives is to be able to run the REST test suite with PHP >= 7 event with a 5.3 server in order to improve the execution time.
Todo:
- No longer use internal API for tokens
- No longer use internal API for configuration change
- Upgrade to PHP7 for runner (so it's hard to import code from Tuleap + it's faster)