Adding Support for Arachni integration

[caglarsayin]

It will be certainly helpful for the people who want to follow security tests with CI tools, and without a doubt Arachni is the one of the best dynamic application testing suite on the market available and free.

I would be pleasure for me to work with you in this project also.

[mathias-nyman]

As an enhancement, this one is quite analog to adding support for Zap; Issue #14, so have a look at the comments there before starting on a patch. Contributions are much welcome :)