fix sms_message when it is none

examples/device/conf.py

 app_key = u'6be9204c30b9473e87bad4dc'
-master_secret = u'8aae478411e89f7682ed5af6'
+master_secret = u'9349ad7c90292a603c512e92'

examples/push/conf.py

 app_key = u'6be9204c30b9473e87bad4dc'
-master_secret = u'8aae478411e89f7682ed5af6'
+master_secret = u'9349ad7c90292a603c512e92'

examples/push/example_audience.py

@@ -7,6 +7,7 @@ push.audience = jpush.audience(
             jpush.tag("tag1", "tag2"),
             jpush.alias("alias1", "alias2")
         )
-push.notification = jpush.notification(alert="Hello, world with audience!")
+push.notification = jpush.notification(alert="Hello world with audience!")
 push.platform = jpush.all_
+print push.payload
 push.send()

jpush/push/core.py

@@ -22,12 +22,13 @@ class Push(object):
         data = {
             "audience": self.audience,
             "platform": self.platform,
-            "sms_message":self.smsmessage,
         }
         if (self.notification is None) and (self.message is None):
             raise ValueError("Notification and message cannot be both empty")
         if self.notification is not None:
             data['notification'] = self.notification
+        if self.smsmessage is not None:
+            data['sms_message'] = self.sms_message
         if self.options is not None:
             data['options'] = self.options
         if self.message is not None: