Add missing classes

[JamieBuckell]

New classes and changes to improve functionality, detailed below:

• src/Auth.php
  • Updated url to .com over .net
  • Added the ability to use the .eu option for connecting to the API
• src/Response/JSON.php
  • Added support for 400 Bad Request error handling
  • Return the created item id when calling API using PUT method
• src/Role.php
• tests/RoleTest.php
  • New classed for Teamwork Roles
• src/Tag.php
• tests/TagTest.php
  • New class for Teamwork Tags
• tests/functions.php
  • Altered project method to allow for project status to be passed, some tests require an active project