Always use fakes_v1_1 for heat.tests.v1_1 fakes import

In some places there is import fakes from heat.tests.v1_1
as fakes_v1_1 and it's necessary because of importing
heat.tests.fakes. This patch makes all tests use 'fakes_v1_1'
for this import.

Change-Id: Ic20b4b0c1d66c088cb023585323404fe16b00097
Merge "Always use fakes_v1_1 for heat.tests.v1_1 fakes import"