corrected ArithmeticError typo, added another ArithmeticError instance
NF: added check_integrity method to GraphPartition, check no empty partitions
NF: added check for NaNs to check_integrity GraphPartition method
RF: update check_integrity docstring
RF: Remove random_mod_old method and refs to module_merge method
NF: Added check_integrity method to GraphPartition object
BF: Fix for correct call to check_integrity method, in debug or extra_info mode
Merge pull request #6 from kbegany/edits

Added check_integrity method to GraphPartition to check for empty or nan partitions