remove template platform from function.json schema

Author: Matt Mason

schemas/json/function.json

@@ -410,9 +410,8 @@
         },
         "platform": {
           "type": "string",
-          "description": "The notification platform to target.",
+          "description": "The notification platform to target. Sends template notification if platform is omitted.",
           "enum": [
-            "template",
             "apns",
             "adm",
             "gcm",