v5.3.0

• Added $applyShippingRules option to Client::createLabel() to select a shipping method based on rules configured in Sendcloud (#35). Thanks @linaori!
• Added Client::getParcelDocument() to obtain exotic documents labels in various formats (#32). Thanks @linaori!
• BC Break: protected method Client::getParcelData has been renamed to createParcelData() with default options for all arguments.