Update get image members tests

*Updated get_image_members module
-Updated tests due to behavior, fixture and config changes
-Updated test steps
*Updated get_image_members_negative module
-Updated tests due to behavior, fixture and config changes

Change-Id: Idac5ab6fd57cad02ac058acaeeb2062004a3ffeb
Rename get_task_schema module

*Removed get_task_schema module to rename it
*Added test_get_task_schema module

Change-Id: I1e9af952c19a079951687c690bd6f0bdfead843a
Merge "Rename get_task_schema module"
Merge "Update get image members tests"