Add Renew and GetPricing methods

Add a few more official Namecheap supported methods to the API.
Update docblock for domainName function

$value is limited to 70 characters and can only be a string.
Add return call for Domain Renew get method

No return was stated for the getter, meaning that it wouldn't function properly.
Add return call for Domain Create get method
Merge branch 'HuisingaWS-master'