2.2.1 Improvements

- Improved code formatting
- Updated docblock `@link`s to related API documentation for all methods
- Changed `searchClients()` to use `/searches/suggestions` endpoint
- Removed `updateShipment()` and `updateOrder()`
- Added methods: `cancelShipment()`, `generateAirbill()`, `getAirbill()`, `emailAirbill()`, `getShipmentSugestion()`, `createQuotes()`

Use $_defaultPagination array for paginated endpoints

Remove defaults from listCategories() vecause it does not paginate

Update changelog