deps: update remark-lint to version 5.2.0 (#494)

https://greenkeeper.io/

package.json

@@ -69,7 +69,7 @@
     "node-fetch": "1.6.3",
     "nyc": "8.3.2",
     "remark-cli": "2.1.0",
-    "remark-lint": "5.1.0",
+    "remark-lint": "5.2.0",
     "remark-preset-lint-recommended": "1.0.0",
     "sinon": "1.17.6"
   }