Rename the parser module

[jackprogramsjp]

Traceback (most recent call last):
  File "main.py", line 86, in <module>
    main()
  File "main.py", line 58, in main
    Parser = parser.Parser(tokens)
AttributeError: module 'parser' has no attribute 'Parser'

This is gonna occur because Python already has a "parser" module. Please rename the parser module.