Lock marked version due to bug

markedjs/marked#1218

Author: kornelski

package.json

@@ -43,7 +43,7 @@
     "cookie-parser": "^1.4.3",
     "express": "^4.16.3",
     "express-session": "^1.15.6",
-    "marked": "^0.3.9",
+    "marked": "0.3.12",
     "mocha": "^3.5.3",
     "multer": "^1.3.0",
     "should": "^11.2.0",