Add more tests for FakeRedis SCAN.
Add more tests for FakeRedis SCAN.

TouK/vumi,vishwaprakashmishra/xmatrix,TouK/vumi,vishwaprakashmishra/xmatrix,harrissoerja/vumi,harrissoerja/vumi,harrissoerja/vumi,TouK/vumi,vishwaprakashmishra/xmatrix