Improve README and fix mac os issue

MANIFEST.in

 recursive-include mjtest *.py
 README.mdwn
 LICENCE
+setup.py
+mjt.py
\ No newline at end of file

README.mdwn

@@ -5,7 +5,7 @@ A test runner (and suite) for the MiniJava compiler (and its parts) written in t
 
 It's heavily inspired by Sisyphus (and uses some of its code)
 
-__Please contribute to the test cases__
+__Please contribute test cases.__
 
 Test modes
 ----------
@@ -56,12 +56,15 @@ git clone https://github.com/mj3-16/mjtest
 cd mjtest
 ```
 
+To get colored output install the python3 module `termcolor`.
+
+
 ### Usage
 Output of the `./mjt.py --help`
 
 ```
-usage: mjtest [-h] [--tmp_dir] [--test_dir] [--only_incorrect_tests]
-              [--parallel] [--timeout] [--report_dir] [--log LOG]
+usage: mjt.py [-h] [--only_incorrect_tests] [--parallel]
+              [--log_level LOG_LEVEL]
               {syntax,semantic,exec} MJ_RUN
 
 MiniJava test runner
@@ -81,10 +84,12 @@ optional arguments:
   --log LOG             Logging level (error, warn, info or debug)
 ```
 
+For Windows users: Using environment variables doesn't work and you have to use prefix `./mjt.py` with `python`.
+
 ### Example usage
 Assuming you want to run the syntax tests and your MiniJava base folder is `~/code/mj` then run
 ```
-MJ_RUN="~/code/mj/run" mjtest syntax
+MJ_RUN="~/code/mj/run" ./mjt.py syntax
 ```
 This will…
 - … create reports in a folder named after the current date and time inside the `reports` folder

mjt.py

-#!/usr/bin/python3
+#!/usr/bin/env python3
 
 import sys
 from os.path import dirname, realpath