fix(package): update react-content-loader to version 5.0.4

Closes #1245

Author: greenkeeper[bot]

package.json

@@ -36,7 +36,7 @@
     "node-polyglot": "^2.3.1",
     "node-sass": "^4.12.0",
     "react": "^16.6.3",
-    "react-content-loader": "^3.4.1",
+    "react-content-loader": "^5.0.4",
     "react-dom": "^16.6.3",
     "react-markdown": "^4.1.0",
     "react-router-dom": "^4.3.1",