from: twill-api
to: twill-discovery-api
evidence:
 - file: "twill-api/src/main/java/org/apache/twill/api/TwillContext.java"
   contains "import org.apache.twill.discovery.DiscoveryServiceClient;"

from: twill-api
to: twill-discovery-api
evidence:
 - file: "twill-api/src/main/java/org/apache/twill/api/TwillController.java"
   contains "import org.apache.twill.discovery.Discoverable;"