Added Bandit BLA implmentation

********* PEOPLE *************
Primary reviewer: @sc932 

Reviewers: @suntzu86 

********* DESCRIPTION **************
Branch Name: norases_373_bla_bandit
Ticket(s)/Issue(s): #373 

********* TESTING DONE *************
make test
make style-test
this is the same as UCB right?  i guess there isn't really a way to generalize this more since UCB and BLA are otherwise unrelated (i think? is that true?)