modified __eq__ method to return False if compared to some other type of variable
Minor correction in doctest
tests for TreeCPD #139
adds more tests for TreeCPD class
adds a ValueError condition
adds a ValueError condition #139
Merge branch 'dev' of https://github.com/ankurankan/pgmpy into dev
Merge pull request #146 from ankurankan/dev

Tests and minor correction in TreeCPD