Rename new_user method to create_user to match CRUD actions.

Replaced new_user method name with create_user.
Added stub method with deprecated notice for new_user.
Update method name to create_user in user tests
Rename new_post route in custom post type class to match parent class create_post method.
Fix stub method name of what should be new_user
Merge pull request #377 from WP-API/issue-377

Rename CustomPostType::new_post to create_post
Revert test variable names in post and user tests.
Merge pull request #376 from WP-API/issue-376

Rename WP_JSON_Users::new_user to create_user
Fix jsonp content-type response header

Incorrectly sends application/json rather than application/javascript on a jsonp request which breaks strict mime handling. In response to error: Refused to execute script from '...url...' because its MIME type ('application/json') is not executable, and strict MIME type checking is enabled.
Alter installation steps to use wp-cli for plugin & permalink setup

WP-CLI is available within Chassis, so using it (via vagrant ssh) to
activate the plugin and set permalinks makes setup slightly faster
post 'parent' value should be null rather than zero if unset

Having a field be either an integer or a nested object makes parsing more complicated. Furthermore, knowing that a parent ID of "0" means that a post has no parent is WordPress inside knowledge that should not leak through the API.
Merge pull request #390 from kadamwhite/use-wp-cli-to-set-permalink

Alter installation steps to use wp-cli for plugin and permanlink setup
Add license.txt file with license terms for #384
Merge pull request #391 from maxcutler/patch-2

post 'parent' value should be null rather than zero if unset
Merge pull request #393 from WP-API/license

Add license.txt file with license terms for #384
Update README.md

Update Testing procedures to include the running provision step before running the testing suite
Offload WordPress installation to bash script so it can be reused
Run tests against single site and multisite
Support for running tests in a few ways
Change our plugin activation test
Merge pull request #396 from ironpaperweight/patch-1

Update README.md to include provision step for testing suite.