fix(package): update styled-components to version 2.2.3

Closes #47

Author: greenkeeper[bot]

package.json

@@ -77,7 +77,7 @@
     "react-helmet": "5.1.3",
     "react-router-dom": "4.1.2",
     "serialize-javascript": "1.4.0",
-    "styled-components": "2.1.2",
+    "styled-components": "2.2.3",
     "user-home": "2.0.0",
     "uuid": "3.1.0"
   },