Loosened lumen dependency to greater than 5.3

v0.3.3

Added API spec.

v0.3.2

Fixed typo in controller name.
Ensured explicit dependency on Lumen 5.3.x.

Fixed legacy array syntax usage

Added date and string handling traits.

Renamed test class.
Added tests for exception handling trait, date trait and string trait.

Tidied up some use statements.

Tweaked README.

Added unit tests.

Initial Release