B2 Sdk Php Versions Save

Changes the authentication domain to backblazeb2.com.

Renamed internal method authoriseAccount to authorizeAccount to suit B2 naming.

Added extra metadata to file objects. Optimize listFiles() method.

• Support for PHP 5.5, previously the package only supported PHP 5.6
• Hooked up Travis CI and Style CI to help with the future maintainability of the project

Fixed an issue where uploads would not be sent correctly when providing a file resource to the upload() method.