add linucb policy

Author: ddbourgin

numpy_ml/bandits/policies.py

@@ -414,7 +414,7 @@ def __init__(self, alpha=1):
 
         Notes
         -----
-        LinUCB is only defined for :class:`ContextualLinearBandit<numpy_ml.bandits.bandits.ContextualLinearBandit>`.
+        LinUCB is only defined for :class:`ContextualLinearBandit<numpy_ml.bandits.bandits.ContextualLinearBandit>` environments.
 
         References
         ----------