chore(package): update docdown to version 0.7.0 (#164)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -23,7 +23,7 @@
   },
   "devDependencies": {
     "coveralls": "^2.11.12",
-    "docdown": "~0.6.1",
+    "docdown": "~0.7.0",
     "istanbul": "0.4.4",
     "qunit-extras": "^2.1.0",
     "qunitjs": "^2.0.1",