Removed unused imports from plotting_utils.
Removed unused imports from plotting_utils.

poppingtonic/BayesDB,poppingtonic/BayesDB,poppingtonic/BayesDB,JDReutt/BayesDB,poppingtonic/BayesDB,poppingtonic/BayesDB,JDReutt/BayesDB,JDReutt/BayesDB,JDReutt/BayesDB,JDReutt/BayesDB