Test that AuthenticationError is an HTTPError.
Test that AuthenticationError is an HTTPError.

ww9rivers/splunk-sdk-python,kkirsche/splunk-sdk-python,splunk/splunk-sdk-python,splunk/splunk-sdk-python,sullivanmatt/splunk-sdk-python,kkirsche/splunk-sdk-python,kkirsche/splunk-sdk-python,kkirsche/splunk-sdk-python,lowtalker/splunk-sdk-python