chore(package): update @types/js-yaml to version 3.12.3

Closes #70

Author: greenkeeper[bot]

package.json

@@ -82,7 +82,7 @@
     "@types/express": "4.16.0",
     "@types/fs-extra": "5.0.4",
     "@types/helmet": "0.0.42",
-    "@types/js-yaml": "3.11.2",
+    "@types/js-yaml": "3.12.3",
     "@types/mocha": "5.2.5",
     "@types/node": "10.12.12",
     "@types/request": "2.48.1",