Added doc test examples for repr and payoff_matrices
Added tests and an explenation to generate_utilities
Added doctests and slightly refactored row_cond_dominance
tidied a test slightly
Added doctests to solve_indifference
Made tests for indifference a bit more verbose
Added another test to is_NE
minor refactoring
minor minor refactoring
Have added doctest to parser
Changed formatting to python 3 style