tests: support for coverage and travis

Adds support for code coverage, Travis CI, improves README file, and increases version number preparing for forthcoming release.  
@romanchyla For our use cases, it is not really needed.  Hence, if you have a branch in some state, maybe you can push a PR so someone can look at it.  However, we don't reallly need it...

BTW, we should probably turn all TODO items from code and documentation into GitHub issues, but I did not want to do it as part of this commit.  It can come later.