Add support for vendor prefixes

[AlexOuttaspace]

React uses PascalCase to handle vendor prefixed inline styles. This means that if in your project you encountered a situation, where you need to add something like -webkit-text-stroke-color, this library wont be able to handle it and as a result JSX element will receive this css property with camelCased key webkitTextStrokeColor.

I would like to make a pull request that addresses this issue by slightly changing the behaviour of functions used to change casing of css properies' keys.

I have already forked this project and made some changes

[betancourtl]

Hey thx for submitting the Pull Request. I definitely missed that case. I'm willing to merge this as long as there are some unit tests and all the functionality stays the same. I will take a look at this sometime tonight and if everything seems good I can merge.

[AlexOuttaspace]

@webdeveloperpr I've updated the code and added some tests. I also tested this in my own project and everything seems to be working fine.