chore(demo): Lock Splunk demo to version 8.0.2.1
chore(demo): Lock Splunk demo to version 8.0.2.1

There is an error loading the demo on Splunk 8.0.3 and higher, so I had
to lock the demo to Splunk 8.0.2.1.

PaloAltoNetworks-BD/SplunkforPaloAltoNetworks