Pythonwhat refactored

Huge refactor.

Version for testing

New version to test CI functionality.

First release

Basically, pythonwhat contains similar functionality as testwhat, but with some functionality specific to the syntax and spirit of the Python programming language.
In the recent weeks, following things have been added:

• Mistake highlighting; the function or object you're making a mistake is highlighted in DataCamp's editor. This feature depends on the functions you use; not all of them can show the line of the mistake (e.g. test_output_contains())
• Improvements of test_function: By doing different test_function() calls, you can choose custom feedback messages for different arguments or keywords that are incorrectly defined. By setting do_eval=None, you can simply check if args and keywords have been specified, but you don't check the correspondence of these parameters with the solution.
• Fix for test_function(), where importing a specific function from a package with from x import y works now; you should point to that function specifically now inside test_function(), with test_function("x.y").
• Overall addition of tests for robustness.