Merge pull request #933 from plotly/renovate/css-loader-3.x

Update dependency css-loader to v3

Author: nicolaskruchten

package.json

@@ -47,7 +47,7 @@
     "babel-jest": "24.8.0",
     "babel-loader": "8.0.6",
     "babel-plugin-module-resolver": "3.2.0",
-    "css-loader": "2.1.1",
+    "css-loader": "3.0.0",
     "cssnano": "4.1.10",
     "enzyme": "3.9.0",
     "enzyme-adapter-react-16": "1.13.2",