fix: package.json & .snyk to reduce vulnerabilities

The following vulnerabilities are fixed with a Snyk patch:
- https://snyk.io/vuln/npm:marked:20170907

Latest report for snyk/goof:
https://snyk.io/test/github/snyk/goof

.snyk

@@ -0,0 +1,8 @@
+# Snyk (https://snyk.io) policy file, patches or ignores known vulnerabilities.
+version: v1.8.0
+ignore: {}
+# patches apply the minimum changes required to fix a vulnerability
+patch:
+  'npm:marked:20170907':
+    - marked:
+        patched: '2017-11-02T03:53:05.687Z'

package.json

@@ -10,7 +10,9 @@
   "scripts": {
     "start": "node app.js",
     "build": "browserify -r jquery > public/js/bundle.js",
-    "cleanup": "mongo express-todo --eval 'db.todos.remove({});'"
+    "cleanup": "mongo express-todo --eval 'db.todos.remove({});'",
+    "snyk-protect": "snyk protect",
+    "prepublish": "npm run snyk-protect"
   },
   "dependencies": {
     "body-parser": "1.9.0",
@@ -36,9 +38,11 @@
     "optional": "^0.1.3",
     "st": "0.2.4",
     "stream-buffers": "^3.0.1",
-    "tap": "^5.7.0"
+    "tap": "^5.7.0",
+    "snyk": "^1.47.0"
   },
   "devDependencies": {
     "browserify": "^13.1.1"
-  }
+  },
+  "snyk": true
 }