Add qpid-python to test-requires

The qpid notification tests are not run if the qpid-python package
is not installed.  This change adds it to the test-requires list
and removes the check for it since it should always be present.

Fixes bug 1173380

Change-Id: I2763e320e6018fde196c903f515920ad33f28aa6
Merge "Add qpid-python to test-requires"