Sped up all Db Tests. Now they run in less than 6 secs in total
Merge branch 'dev' into Developer-Utilities
Merge branch 'Developer-Utilities' into 74193950
delete unused images
completed optimisation for all DbTests
speeding up logic tests
sped up CoursesLogicTest
sped up SessionsLogicTest
fixed dependency problem. sped up studentsLogicTest
sped up instructorsLogicTest
sped up feedbackQuestionsLogicTest
sped up feedbackResponsesLogicTest
sped up submissionLogicTest
sped up EvalEmailTaskQueueTest
sped up FBSessionEmailQueueTest
sped up SubmissionsAdjustmentTest
sped up SubmissionsTaskQueueLogicTest
fixed a dependency in BackDoorTest.
reduced more dependencies
add courses info for account deletion confirmation dialogue