exit before starting up if exp name is invalid

refs: #3115

Change-Id: I901ac7b951bc21ba8069b5b9be2a1d067ba8e61b

bin/minindn

@@ -146,6 +146,10 @@ def parse_args():
         printExperimentNames()
         sys.exit()
 
+    if experimentName is not None and experimentName not in ExperimentManager.getExperimentNames():
+        print("No experiment named %s" % experimentName)
+        sys.exit()
+
     if ctime is None:
         ctime = 60