Fixes #3 and #4.
Modified public API of (hopefully) all classes to accept the tuple S,A,S' which replaces the
previous accepted tuple of S,S',A. In addition, modified underlying implementation in the
same way, mostly to allow handling of probability vectors without the need for strange loops.
New file ProbabilityUtils contains functions to handle probability vectors.
Another change to avoid double comparison problems.
Added .travis.yml file in request to #2
Fixed travis file
Updated travis and reduced boost requirements for building
Update README.md

Now contains travis icon.
Update README.md

Added waffle.io badge and managing issues. Fixes #2.