Add sails-mssql to available database adapters

I updated the readme on my fork for information about running unit tests.   I'm getting a "keyAt" failure in the associations interface tests, but it looks like the mysql0.10rc-7 is having that same failure.  Otherwise the tests for: semantic, queryable, and associations are passing.  

All of my testing was done with sql server 2008, however, I don't foresee any problems with newer versions of sql server.  

Let me know if I need to take any further action!