added isInBoundingBox function

[talha-asad]

Hey,

I really like your module and use it alot, but often times i have to do this stuff in my code, i think it could be a part of the module. Please kindly review and merge this. Once you're done please release a new version so i can officially use this function. I also added some tests to make sure everything is working.

Thanks!

[ro31337]

@davidwood any chance to accept this PR?

[shide1989]

Iwould hope so