Use correct mock object to mock context in test_client
Use correct mock object to mock context in test_client

Change-Id: Ic9d1814ab07383441b89ffe55b3ea1e4c2e2f50a

stackforge/ec2-api,hayderimran7/ec2-api,hayderimran7/ec2-api,openstack/ec2-api,stackforge/ec2-api,openstack/ec2-api