Add mock class for storage backend
Add mock class for storage backend

awest1339/multiscanner,jmlong1027/multiscanner,awest1339/multiscanner,MITRECND/multiscanner,jmlong1027/multiscanner,mitre/multiscanner,MITRECND/multiscanner,mitre/multiscanner,jmlong1027/multiscanner,jmlong1027/multiscanner,awest1339/multiscanner,mitre/multiscanner,awest1339/multiscanner