fix(package): update url-loader to version 2.3.0

Closes #51

Author: greenkeeper[bot]

packages/core/package.json

@@ -18,7 +18,7 @@
     "style-loader": "^0.23.0",
     "terser-webpack-plugin": "^1.2.2",
     "trash": "^4.3.0",
-    "url-loader": "^1.1.1",
+    "url-loader": "^2.3.0",
     "webpack": "^4.19.1",
     "webpack-dev-server": "^3.1.8",
     "webpack-handle-css-loader": "^3.0.1",