Move require of scss to the top level component

jest.json

@@ -8,7 +8,7 @@
   "coverageDirectory": "<rootDir>/coverage",
   "coverageReporters": ["html", "lcov"],
   "moduleNameMapper": {
-    "\\.css$": "<rootDir>/__mocks__/css.js"
+    "\\.s?css$": "<rootDir>/__mocks__/css.js"
   },
   "setupFiles": [
     "<rootDir>/setupJest.js"

src/components/App.js

@@ -5,6 +5,7 @@ import Fullscreen from 'react-full-screen';
 import { I18nextProvider } from 'react-i18next';
 import i18n from '../i18n';
 import WorkspaceArea from '../containers/WorkspaceArea';
+import '../styles/index.scss';
 
 /**
  * This is the top level Mirador component.

src/init.js

 import MiradorViewer from './lib/MiradorViewer';
-import './styles/index.scss';
 
 /**
  * Default Mirador instantiation