Update React to version v15.6 (#3736)

package.json

@@ -74,10 +74,10 @@
     "prop-types": "^15.5.10",
     "punycode": "^2.1.0",
     "rails-ujs": "^5.1.1",
-    "react": "^15.5.4",
+    "react": "^15.6.0",
     "react-addons-perf": "^15.4.2",
     "react-addons-shallow-compare": "^15.5.2",
-    "react-dom": "^15.5.4",
+    "react-dom": "^15.6.0",
     "react-immutable-proptypes": "^2.1.0",
     "react-immutable-pure-component": "^0.0.5",
     "react-intl": "^2.3.0",

yarn.lock

@@ -5513,9 +5513,9 @@ react-docgen@^2.15.0:
     node-dir "^0.1.10"
     recast "^0.11.5"
 
-react-dom@^15.5.4:
-  version "15.5.4"
-  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-15.5.4.tgz#ba0c28786fd52ed7e4f2135fe0288d462aef93da"
+react-dom@^15.6.0:
+  version "15.6.0"
+  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-15.6.0.tgz#8bc23cb0c80e706355b76ca9f8ce47cf7bdfb6d1"
   dependencies:
     fbjs "^0.8.9"
     loose-envify "^1.1.0"
@@ -5711,10 +5711,11 @@ react-virtualized@^9.7.4:
     loose-envify "^1.3.0"
     prop-types "^15.5.4"
 
-react@>=0.14.0, react@^15.5.4:
-  version "15.5.4"
-  resolved "https://registry.yarnpkg.com/react/-/react-15.5.4.tgz#fa83eb01506ab237cdc1c8c3b1cea8de012bf047"
+react@>=0.14.0, react@^15.6.0:
+  version "15.6.0"
+  resolved "https://registry.yarnpkg.com/react/-/react-15.6.0.tgz#c23299b48e30ed302508ce89e1a02c919f826bce"
   dependencies:
+    create-react-class "^15.5.2"
     fbjs "^0.8.9"
     loose-envify "^1.1.0"
     object-assign "^4.1.0"