functional tests for Snapshot Job Processor

grouped tests under following classes,
- TestSnapshotProcessorJobProcessing
- TestSnapshotProcessorPolling
- TestSnapshotProcessorRetentionProcessing
- TestSnapshotProcessorNotifications
- TestSnapshotProcessorImageName

Co-authored-by: Sridevi Koushik <sridevi.koushik@rackspace.com>
Merge pull request #297 from venkateshsampath/test_job_processor

Functional Tests for Snapshot Job Processor