use updated mailgun adapter

package-lock.json

@@ -3864,13 +3864,13 @@
       "integrity": "sha1-SrTJoPWlTbkzi0w02Gv86PSzVXE=",
       "dev": true,
       "requires": {
-        "duplexer": "~0.1.1",
-        "from": "~0",
-        "map-stream": "~0.1.0",
+        "duplexer": "0.1.1",
+        "from": "0.1.7",
+        "map-stream": "0.1.0",
         "pause-stream": "0.0.11",
-        "split": "0.3",
-        "stream-combiner": "~0.0.4",
-        "through": "~2.3.1"
+        "split": "0.3.3",
+        "stream-combiner": "0.0.4",
+        "through": "2.3.8"
       },
       "dependencies": {
         "split": {
@@ -3879,7 +3879,7 @@
           "integrity": "sha1-zQ7qXmOiEd//frDwkcQTPi0N0o8=",
           "dev": true,
           "requires": {
-            "through": "2"
+            "through": "2.3.8"
           }
         }
       }

package.json

@@ -22,7 +22,7 @@
     "@parse/fs-files-adapter": "1.0.1",
     "@parse/push-adapter": "3.0.0-alpha2",
     "@parse/s3-files-adapter": "1.2.1",
-    "@parse/simple-mailgun-adapter": "1.0.2",
+    "@parse/simple-mailgun-adapter": "1.1.0",
     "bcryptjs": "2.4.3",
     "body-parser": "1.18.3",
     "commander": "2.17.1",