Update file-loader to the latest version 🚀 (#1095)

* chore(package): update file-loader to version 4.0.0

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -78,7 +78,7 @@
     "eslint": "5.16.0",
     "eslint-plugin-jest": "22.5.1",
     "eslint-plugin-react": "7.13.0",
-    "file-loader": "3.0.0",
+    "file-loader": "4.0.0",
     "http-server": "0.11.1",
     "jest": "24.8.0",
     "marked": "0.6.2",