Fixed dependency on trove for int-tests

Cleaned up int-test dependencies so that the core int-test groups
are now registered entirely from trove python module. This enables
adding new int-tests for features in trove without creating a cross
repository dependency in trove-integration.

Change-Id: I13fad1179ea6d576d5b96592c8bf927037f51e7b
Closes-bug: 1343584