Handle the new user creation exceptions

[acamacho82]

Added try/except and unit tests to handle the exception that is not an error #1101

output if SoftLayer_Exception_User_Customer_DelegateIamIdInvitationToPaas occurs

Do you wish to continue? [y/N]: y
Your request for a new user was received, but it needs to be processed by the Platform Services API first. Barring any errors on the Platform Services side, your new user should be created shortly.

output if a different exception occurs:

Do you wish to continue? [y/N]: y
SoftLayerAPIError(SoftLayer_Exception_User_Customer_IamIdAlreadyInvited): Account 11111111 is authenticated by IAMid, and this IAMid already has an active invitation to link to a user in this account.

output when account is not linked to bluemix:

Do you wish to continue? [y/N]: y
:.......................:......................................:...........:.........:
:        Username       :                Email                 :  Password : API Key :
:.......................:......................................:...........:.........:
: user_name_example01   :  user_name_example01@mailinator.com  : Pass@1234 :   None  :
:.......................:......................................:...........:.........:

[coveralls]

Coverage increased (+0.004%) to 91.705% when pulling bcac437 on acamacho82:1101 into 3f5e873 on softlayer:master.

[allmightyspiff]

Fixes #1101

[allmightyspiff]

As of May 3, this error should no longer happen. https://sldn.softlayer.com/release_notes/2019/20190503/