Token service priti

Implemented Basic Token Service.. Wrote Test cases for the same.
Further extensions can be done to set session timeout period and accordingly maintain sessions. But not sure whether session timeout period is responsibility of TokenService or Log In module...
1. In the TokenDb you do not need to abbreviate every operation with the Token term. Simple Create(), Delete(), Get() etc would suffice. 
2. The last method should be GetTokenCount() instead of TokenCount(). Method names should be verbs.