Follow up fix for the TWILL-116 PR to update the comments for constants used in restart commands.

This closes #54 on GitHub.

Signed-off-by: Terence Yim <chtyim@apache.org>
diff --git a/twill-core/src/main/java/org/apache/twill/internal/Constants.java b/twill-core/src/main/java/org/apache/twill/internal/Constants.java
index e3a2194..defd013 100644
--- a/twill-core/src/main/java/org/apache/twill/internal/Constants.java
+++ b/twill-core/src/main/java/org/apache/twill/internal/Constants.java
@@ -48,7 +48,7 @@
   public static final String CLASSPATH = "classpath";
   public static final String APPLICATION_CLASSPATH = "application-classpath";
 
-  /** For runnables instance lifecycle ZK path */
+  /** Command names for the restart runnable instances. */
   public static final String RESTART_ALL_RUNNABLE_INSTANCES = "restartAllRunnableInstances";
   public static final String RESTART_RUNNABLES_INSTANCES = "restartRunnablesInstances";