chore(package): update styled-components to version 3.4.9

Closes #62

Author: greenkeeper[bot]

package.json

@@ -62,7 +62,7 @@
     "lint-staged": "~4.0.2",
     "prettier": "~1.5.3",
     "react": "~16.3.1",
-    "styled-components": "~3.2.5",
+    "styled-components": "~3.4.9",
     "stylelint": "~9.1.3",
     "stylelint-config-standard": "~17.0.0",
     "stylelint-processor-styled-components": "~1.3.1",