TestSuite

=TestSuite
this class implement Test management
* collection
* run
* pretty print (JSon actually). This pretty print will be usefull to use with
  arc unit test API (if needed)

=Test
This class is designed for inheritence
A test should...

Summary:
...implements the Test interfaces

Propose a Test Suite API

Test Plan: see result in tests directory

Reviewers: adrienconrath

Reviewed By: adrienconrath

Subscribers: NicolasDP

Maniphest Tasks: T16

Differential Revision: http://91.121.199.76/D28