Add PHP support with foundation for PHP libraries to load third parties

[felixarntz]

Fixes #39

• PHP classes foundation
• PHP third parties implementation
• Test coverage
• Add docs
• Move JSON files out of JS-specific folders (will be done in a follow up PR)

[adamsilverstein]

@felixarntz - this looks great so far! the main possible improvement would be adding tests although I'm not sure that should be a blocker since the JS side doesn't have them :)

[flashdesignory]

@felixarntz - this looks great so far! the main possible improvement would be adding tests although I'm not sure that should be a blocker since the JS side doesn't have them :)

It's always great to have a new set of eyes on the JS side as well 😄
We do cover the crucial functions with unit tests (utils file), but please let us know if you feel that there are some tests missing.
Personally, I don't think we need 100% test coverage, but should cover the crucial parts to ensure we're delivering the correct output.

[felixarntz]

@housseindjirdeh @adamsilverstein @flashdesignory I've completed the remaining tests so this is now ready for full review.

Regarding documentation, for now I only added a small note to the readme referring to both the JS and PHP implementations. More wasn't really needed at this point, as everything else in the readme applies in both scenarios.

I think it would be useful to add more specific documentation (most importantly a few code examples in both JS and PHP), but that could be done in a separate PR.

[felixarntz]

@housseindjirdeh @adamsilverstein @flashdesignory Friendly ping :)

Any chance we can get this merged in the next 1-2 weeks?