Update react monorepo to v16.4.0

package.json

@@ -4,8 +4,8 @@
   "private": true,
   "dependencies": {
     "classnames": "2.2.5",
-    "react": "16.3.2",
-    "react-dom": "16.3.2",
+    "react": "16.4.0",
+    "react-dom": "16.4.0",
     "react-scripts": "1.1.4"
   },
   "homepage": "https://mythmon.github.io/corsica-tree-status",

yarn.lock

@@ -5412,9 +5412,9 @@ react-dev-utils@^5.0.1:
     strip-ansi "3.0.1"
     text-table "0.2.0"
 
-react-dom@16.3.2:
-  version "16.3.2"
-  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-16.3.2.tgz#cb90f107e09536d683d84ed5d4888e9640e0e4df"
+react-dom@16.4.0:
+  version "16.4.0"
+  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-16.4.0.tgz#099f067dd5827ce36a29eaf9a6cdc7cbf6216b1e"
   dependencies:
     fbjs "^0.8.16"
     loose-envify "^1.1.0"
@@ -5470,9 +5470,9 @@ react-scripts@1.1.4:
   optionalDependencies:
     fsevents "^1.1.3"
 
-react@16.3.2:
-  version "16.3.2"
-  resolved "https://registry.yarnpkg.com/react/-/react-16.3.2.tgz#fdc8420398533a1e58872f59091b272ce2f91ea9"
+react@16.4.0:
+  version "16.4.0"
+  resolved "https://registry.yarnpkg.com/react/-/react-16.4.0.tgz#402c2db83335336fba1962c08b98c6272617d585"
   dependencies:
     fbjs "^0.8.16"
     loose-envify "^1.1.0"