Fix/some additional tests

Not necessarily all for inclusion, but for discussion.  a couple of things:
1/ remove some unneeded files - composer.lock and netbeans directory
2/ some additional tests where you don't have any, but principally to illustrate what I was talking about in my 'issue' request earlier.  Given floating point is a bit tricky in PHP, I do think that using the 'continued fraction' method of float conversion may give better results.  Note that setting the $tolerance to an even smaller number can give better results at the expense of computation time.  

If you like the idea, I can refactor to replace the existing fromFloat() method and do another pull request.