CLDCONNECT-2162 - https://www.mulesoft.org/jira/browse/CLDCONNECT-2162

1. Updated the InterOp testate files with the new message processors.
2. Updated USAGE.md
3. Updated the demo for retrieve-file operation and README.md
Merge pull request #13 from mulesoft/feature/CLDCONNECT-2162_Updated_InterOp_Files

CLDCONNECT-2162 - https://www.mulesoft.org/jira/browse/CLDCONNECT-2162