fix(package): update @gridsome/source-filesystem to version 0.4.1

Closes #2

Author: greenkeeper[bot]

package.json

@@ -10,7 +10,7 @@
   "dependencies": {
     "@gridsome/plugin-google-analytics": "^0.1.0",
     "@gridsome/remark-prismjs": "^0.0.5",
-    "@gridsome/source-filesystem": "^0.3.0",
+    "@gridsome/source-filesystem": "^0.4.1",
     "@gridsome/transformer-remark": "^0.2.0",
     "gridsome": "^0.5.0"
   },