Handle new user creation exceptions

[allmightyspiff]

https://github.com/softlayer/softlayer-python/blob/master/SoftLayer/managers/user.py#L240

create_user needs to handle the exception that is not an exception, oftLayer_Exception_User_Customer_DelegateIamIdInvitationToPaas

https://softlayer.github.io/reference/services/SoftLayer_User_Customer/createObject/

Ideally, print out some message about the creation being mostly done, waiting on some PaaS acceptance. This only effects accounts that are fully linked so might be a bit hard to test.

[allmightyspiff]

Fixed in #1115