CreateOpsServer.py does not catch errors when creating new ArcGIS Server site

Encountered issue with authorizing ArcGIS Server, which prevented the ArcGIS Server site from being created; an error message was displayed to standard output, but script did not pause.

This is the generated error:

--Create ArcGIS Server Site...

```
-Setting up required properties for config store...
Done.

-Creating Python dictionaries representing server directories
(arcgiscache, arcgisjobs, arcgisoutput, arcgissystem)...
Done.

-Serializing server directory information to JSON...
Done.

-Constructing URL to create a new site...
Done.

-Setting up parameters for the request to create new site...
Done.

-Making request to create new site...
```

Error: JSON object returns an error. {u'status': u'error', u'code': 500, u'messages': [u'Failed to create the site. The machine does not have a valid license. Please authorize ArcGIS Server by clickin
g Start > Programs > ArcGIS > ArcGIS for Server > Software Authorization']}
ERROR: Error returned by operation. {"status":"error","messages":["Failed to create the site. The machine does not have a valid license. Please authorize ArcGIS Server by clicking Start > Prog
rams > ArcGIS > ArcGIS for Server > Software Authorization"],"code":500}

Start in CreateOpsServer.py at the request that creates the ArcGIS Server site and compare its handling of the returned error object with the displayed output. Reproduce the invalid-license response if possible, then verify that the script handles the failed operation as intended instead of continuing without pausing.

Written by the indexing model from the issue text.