Move bw_usage_* tests in test_db_api to own test case.

There is bw_usage_* tests in old mixed DbApiTestCase.
This patch moves them to its own test case BwUsageTestCase.

Missing test_bw_usage_get added.

blueprint db-api-tests

Change-Id: Ie79d31694d9c72d9d6f43772aeadff200987646c
Move test_security_group_update to SecurityGroupTestCase.

There is security group update test in old mixed
DbApiTestCase. This patch moves this test to its
own test case SecurityGroupTestCase.

blueprint db-api-tests

Change-Id: Icf64651dbea4d97480a218140abc6e72166713d3
Move *_ec2_* tests in test_db_api to own test case.

There is *_ec2_* tests in old mixed DbApiTestCase.
This patch moves them to its own test case Ec2TestCase.

Also missing tests added to new test case.

blueprint db-api-tests

Change-Id: I2d14cd36873c736411f6cc587aa52dbdb1296445
Move test_stringified_ips to InstanceTestCase.

There is test_stringified_ips for instance_*
methods in old mixed DbApiTestCase.
This patch moves this test to InstanceTestCase.

blueprint db-api-tests

Change-Id: I771ccec9f41480c8aa90e18b60cc8d75137027d3
Move a migration test to MigrationTestCase.

There is test_migration_get_unconfirmed_by_dest_compute
test in old mixed DbApiTestCase. This patch moves this test
to its native test case MigrationTestCase.

DbApiTestCase renamed as DecoratorTestCase because no
db api methods tests remained in this test case.

blueprint db-api-tests

Change-Id: Ibe6ebf266a2f4694fb218266ba644be825889907
Add a new GroupAffinityFilter

1) Add a new filter to schedule the instance on to host from a set
   of group hosts
2) Update filter_scheduler.rst to add the new GroupAffinityFilter
   filter description

Implements blueprint group-affinity-filter

DocImpact

Change-Id: Iba59764e692cd1d3bc80521ba5a4412f2bebb168
Merge "Move bw_usage_* tests in test_db_api to own test case."
Merge "Move test_security_group_update to SecurityGroupTestCase."
Merge "Move *_ec2_* tests in test_db_api to own test case."
Merge "Add a new GroupAffinityFilter"
Merge "Move test_stringified_ips to InstanceTestCase."
Merge "Move a migration test to MigrationTestCase."
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp