Whitespace: fix spacing within parens
Add registerType custom post type request method generator

See #25, fixes #7
Add example usage to registerType doc block
Expand README to cover the core WP instance methods & registerType
Add an arbitrary .url() method to base WP object (Closes #47)
Pass WP instance options through to .registerType() and .url() requests

Forgetting to do this would mean these requests would be unbound from the
provided endpoint, authentication, etc
Add a .root() method for querying custom endpoints

WooCommerce, and soon other plugins, will be adding custom endpoints to
the API. This method is only a stopgap, but .root() provides a way to
specify a request against one of these custom API endpoints by providing
a root-relative path to the new endpoint.

Note that no path interpolation will occur, so the provided path must be
a dumb string, not a custom(/:url)(/:template) of any sort!
Add tests for updating supported methods with .id in Posts and Page requests
Add a /media endpoint handler method

wp.media() creates a MediaRequest instance, which can be used to retrieve

1. a Media collection, from /media, or
2. a Media object, from /media/<id>

Closes #39
Update README with media methods
Change how authentication works in WPRequest
Force authentication where it would be convenient
Add tests for situations where we force basic authentication