Fix: WhiteBox server leak

Deleteting the server explicity in the tearDownClass.

Fixing Bug 1180852

Change-Id: If94c82717832ef35473840b793fcfd6871bbf4bd
Quantum client should not be conditional

* requirements.txt enumerates it
* Does not have any special dependency

Change-Id: Ib77ad33deda5920790f7a2262f2665e4b4b15a6d
Merge "Quantum client should not be conditional"
Merge "Fix: WhiteBox server leak"