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.
Hello, I have finally some time to reply to you.

* `composer.lock`:

  > Commit your application's composer.lock (along with composer.json) into version control.
   
  Suggestion from the official [Composer documentation](https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file)
* `nbproject`: I only exclude `nbproject/private` as suggested [here](http://docs.oracle.com/cd/E50453_01/doc.80/e50452/create_japps.htm#NBDAG445). I don't think it hurts and makes it easier for people that use NetBeans IDE (e. g. me). The `nbproject/phpcsmd.properties` should be ignored, since it is a plugin related file.
* I will look at the code related stuff and will maybe merge it later (I will update the Travis CI integration too). I will not merge this one, since I decide against point one and against point two partially. Two separate PRs would have been better.