Feature/release 1.5.0 (#40)

* Bump Tested up to: 5.0

* Bump version to 1.5.0

Support for field usage attributes in permalink definition (#31)

* Support for permalink fields attributes added.

* Tests added for field attributes. Tests namespaced.

* Include relatively in main.

* Fix the bug which sanitizes unwanted spaces in permalink structure.

* Bump version to 1.4.0