Add more testing and fix some errors

[peter279k]

Thank you for providing this great math package.Here is the changed log is as follows:

Changed log

• add more testing and improve code coverage.
• fix some errors during the testing.
• hook the coveralls and it's the code coverage service.
• set the configuration for the .travis.yml. set the dist is precise because of this issue. And it can test well in PHP 5.3.

BTW, I think the coding style should be unified. Perhaps we can use PHP-CS-Fixer or hook the StyleCI service and set the PSR-2 coding style. What do you think?

Thanks.

[malenkiki]

Whooooaa ! Thank you very very very much for this great PR!

I will check it later this day or tomorrow when I have some time.

[malenkiki]

Great PR, but I havesome comment like you have see ;-)

Many thanks!

[peter279k]

Hi @malenkiki, thank you for your review. I will modify them at my available time.

Thanks!