chore(package.json): update markdown-doctest to 0.3.1

Author: staltz

package.json

@@ -122,7 +122,7 @@
     "karma-sauce-launcher": "0.3.0",
     "lodash": "4.1.0",
     "madge": "^0.5.3",
-    "markdown-doctest": "^0.3.0",
+    "markdown-doctest": "^0.3.2",
     "minimist": "^1.2.0",
     "mkdirp": "^0.5.1",
     "platform": "1.3.0",