Version 0.3.2

Added validateCredentials method

Version 0.3.1

• Added get/post methods
• Added error helper function

Version 0.3.0

• Removed open-api generator
• Refactored tests to use guzzle client
• Added phpstan check
• Removed ApiException
• Added response helper functions

v0.2.0

• renamed TrackingNumber to Shipment
• enabled guzzle errors
• minor bugfixes