Logging demo README should use mvn exec:java.
Logging demo README should use mvn exec:java.

This now matches the dataset demo, to avoid distracting new users.

cloudera/cdk-examples,yuzhu712/cdk-examples,yuzhu712/cdk-examples,kite-sdk/kite-examples,kite-sdk/kite-examples,cloudera/cdk-examples,kite-sdk/kite-examples