Revise README
Revise README

Add Java and Splunk versions tested for compatibility
https://jira.splunk.com/browse/DVPL-7485
splunk/splunk-sdk-java,splunk/splunk-sdk-java,splunk/splunk-sdk-java,splunk/splunk-sdk-java,splunk/splunk-sdk-java,splunk/splunk-sdk-java