Fixed issue with session clearing. Selected item is set to null
Fixed StartOver interaction and Default interaction. StartOver now calls default interaction after resetting the db. Default interaction uses the itemId of previously selected challenge.
Refactored substitution logic. Moved it to a separate class
Fixed Done interaction to behave like submit interaction when data is submitted and like default interaction if nothing is provided.
Merge branch 'master' of https://github.com/NTechInternational/slap

Conflicts:
	slap/src/main/java/com/ntechinternational/slap/SlapRestImpl.java
Added test for variable replacement code
Merged variable utility class into template class and removed it. Added test case for ensuring that variables are split properly
Added travis support
Added test for visitor Id generation logic.
Modified travis yml for correct config
Added image to readme
Added test for Visitor Id creation logic i.e ./getVisitorId interaction
Debugging travis
Merge branch 'master' of https://github.com/pradhanta/slap
Merge pull request #14 from pradhanta/master

Fixed session clear -> startover, based on prior session, previous state, sentence parsing, done and startover