fix(package): update lodash to version 4.17.12

Closes #47

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "extract-text-webpack-plugin": "1.0.1",
     "findup": "0.1.5",
     "glob": "7.1.1",
-    "lodash": "4.16.6",
+    "lodash": "4.17.12",
     "marked": "0.3.6",
     "minimist": "1.2.0",
     "postcss-advanced-variables": "1.2.2",