RexPro Authentication Fixed

Problem seemed to stem from the "Empty" session default of `None` serializes to \xc0, whereas the spec dictates a byte(16) of \x00

Also Includes:
  - Testing suite updates
  - Requirements updates
  - Coverage script
  - Setup.py updates
  - Python 2 & 3 compatibility -- needs testing - known to work with Python 2.7.5+
  - Improved code coverage
  - PEP8 and formatting
Added TravisCI configuration
travis build fix
version bump with included fixes
Merge remote-tracking branch 'origin/master'