Update styled-components from 2.3.0 to 2.4.0 (#37)

package.json

@@ -56,7 +56,7 @@
         "react": "^16.1.1",
         "react-dom": "^16.1.1",
         "react-hot-loader": "^3.1.2",
-        "styled-components": "^2.3.0"
+        "styled-components": "^2.4.0"
     },
     "devDependencies": {
         "babel-plugin-transform-async-to-generator": "^6.24.1",

yarn.lock

@@ -2906,10 +2906,6 @@ is-function-x@^3.2.0, is-function-x@^3.3.0:
     to-boolean-x "^1.0.1"
     to-string-tag-x "^1.4.2"
 
-is-function@^1.0.1:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/is-function/-/is-function-1.0.1.tgz#12cfb98b65b57dd3d193a3121f5f6e2f437602b5"
-
 is-index-x@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/is-index-x/-/is-index-x-1.1.0.tgz#43dac97b3a04f30191530833f45ac35001682ee2"
@@ -4985,15 +4981,14 @@ strip-json-comments@~2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/strip-json-comments/-/strip-json-comments-2.0.1.tgz#3c531942e908c2697c0ec344858c286c7ca0a60a"
 
-styled-components@^2.3.0:
-  version "2.3.0"
-  resolved "https://registry.yarnpkg.com/styled-components/-/styled-components-2.3.0.tgz#d9cf4574e140fea6426e48632ed0ca4494537718"
+styled-components@^2.4.0:
+  version "2.4.0"
+  resolved "https://registry.yarnpkg.com/styled-components/-/styled-components-2.4.0.tgz#086d0fd483d54638837fca3ea546a030b94adf75"
   dependencies:
     buffer "^5.0.3"
     css-to-react-native "^2.0.3"
     fbjs "^0.8.9"
     hoist-non-react-statics "^1.2.0"
-    is-function "^1.0.1"
     is-plain-object "^2.0.1"
     prop-types "^15.5.4"
     stylis "^3.4.0"