Made methods into class methods for interpreter classes. Also modified tests to reflect the change.
Restructuring haskell version of interpreter. Completed new version of lexer. Changed test to reflect new design.
Moved Python interpreter to Untyped, in anticipation for trying to create a typed interpreter.
Moved Haskell interpreter to untyped. Renamed lambda_interpreter.hs to Interpreter.hs to play nice with module import
Created outline for Haskell parser and evaluator.
Updated README to reflect current functionality.