Overhaul

[robbiet480]

Big update, lots and lots of little changes to bring this library up to the latest WordPress API standards. Here's a list:

• Better stability and predictability (IMHO)
• All tests passing, including some of the disabled ones
• Use context
• Pagination
• Comments on all exported functions, variables, etc.
• Examples for the three primary authentication methods (oAuth 1.0a, oAuth 2.0/JWT, Basic Auth/Application Passwords)
• Replacing gorequest with net/http (for context and fixing weird query string edge cases)
• Initial work to accept structs for endpoint options instead of maps
• A lot of other little fixes too numerous to count

Thanks @dannynash @o1egl for your work on this!

@sogko I'm hoping you can accept this pull request and possibly transfer ownership of the repo to me. I'm building a whole business on top of go-wordpress, so I expect to be a maintainer of it for a long time to come.

Thanks all!

[ralph327]

I'm going to make a sacrifice to the open-source gods so that this PR is merged and that @robbiet480 becomes the new maintainer.