Update package.json

Fixes flatmap-stream vulnerability fix:

dominictarr/event-stream#116

Author: cdifulvio

package.json

@@ -80,7 +80,7 @@
     "chalk": "^1.1.1",
     "commander": "^2.9.0",
     "debug": "^2.2.0",
-    "event-stream": "^3.3.2",
+    "event-stream": "^3.3.4",
     "form-data": "^1.0.0-rc3",
     "fs-readfile-promise": "^2.0.1",
     "fs-writefile-promise": "^1.0.3",