fix(package): update styled-components to version 5.1.0

Closes #2

Author: greenkeeper[bot]

package.json

@@ -6,7 +6,7 @@
     "react": "^16.12.0",
     "react-dom": "^16.12.0",
     "react-scripts": "3.2.0",
-    "styled-components": "^4.4.1"
+    "styled-components": "^5.1.0"
   },
   "scripts": {
     "start": "react-scripts start",