Add ERROR to list of log level options. (#1699)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

pantheon/src/main/java/tech/pegasys/pantheon/cli/PantheonCommand.java

@@ -510,7 +510,7 @@ public class PantheonCommand implements DefaultCommandValues, Runnable {
       names = {"--logging", "-l"},
       paramLabel = "<LOG VERBOSITY LEVEL>",
       description =
-          "Logging verbosity levels: OFF, FATAL, WARN, INFO, DEBUG, TRACE, ALL (default: INFO)")
+          "Logging verbosity levels: OFF, FATAL, ERROR, WARN, INFO, DEBUG, TRACE, ALL (default: ${DEFAULT-VALUE})")
   private final Level logLevel = Level.INFO;
 
   @Option(