Added Bandit UCB1-tuned implementation

********* PEOPLE *************
Primary reviewer: @sc932 

Reviewers: @suntzu86 

********* DESCRIPTION **************
Branch Name: norases_366_ucb1_tuned_bandit
Ticket(s)/Issue(s): #366  

********* TESTING DONE *************
make test
make style-test
just to be clear, almost all the code here is moved from the old UCB1 class right? get_ucb_payoff is the only new component?