Fixes #65 by making code python 3 compatible

I used pyflake3 to check and some remaining issues are dealt with
in #66.
Bump version number to 0.5.4
Adaption made by 2to3 and then manual clean out. #65

This should now work under Python 2.7.x AND 3.x
Bumped version to v0.5.5
#65 Byte-String needs to be decoded to work with Python3
#66 convert __cmp__ to __tl__ method

This was suggested in
http://python3porting.com/problems.html#unorderable-types-cmp-and-cmp

Still I get a
```
TypeError: unorderable types: SemanticVersion() < SemanticVersion()
```
But it works fine in Python 2. @mtiller, any idea?
#65 Another Byte-String that needs to be decoded to work with Python3
Bump version number and also add the colorama soft-dependency