Lots a bug squashing in Continuous Integration and code

[*] Added tests to the main class. Runnable as arguments
[*] Fixed Travis CI zipping folders to upload to GitHub which it shouldn't
[*] Fixed a nasty bug which caused the XML Parser to override previous set content
[*] Changed the XML Parser to be able to access resources inside the JAR file
[*] Removed debug prints
[~] Made the toString() method in XMLTag prettier