Update dependency styled-components to v4

package.json

@@ -76,6 +76,6 @@
     "react-redux": "5.0.7",
     "redux": "4.0.0",
     "redux-thunk": "2.3.0",
-    "styled-components": "3.4.5"
+    "styled-components": "4.0.1"
   }
 }