Fix requestAnimationFrame warnings in tests.

package.json

@@ -109,6 +109,7 @@
     "postcss-cssnext": "^3.0.2",
     "postcss-import": "^11.0.0",
     "postcss-loader": "^2.0.7",
+    "raf": "^3.4.0",
     "react-hot-loader": "^3.0.0-beta.7",
     "react-test-renderer": "^16.0.0",
     "style-loader": "^0.18.2",

setupTests.js

@@ -1,3 +1,4 @@
+import 'raf/polyfill';
 import enzyme from 'enzyme';
 import enzymeAdapter from 'enzyme-adapter-react-16';
 

yarn.lock

@@ -7436,6 +7436,12 @@ raf@^3.3.2:
   dependencies:
     performance-now "^2.1.0"
 
+raf@^3.4.0:
+  version "3.4.0"
+  resolved "https://registry.yarnpkg.com/raf/-/raf-3.4.0.tgz#a28876881b4bc2ca9117d4138163ddb80f781575"
+  dependencies:
+    performance-now "^2.1.0"
+
 railroad-diagrams@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/railroad-diagrams/-/railroad-diagrams-1.0.0.tgz#eb7e6267548ddedfb899c1b90e57374559cddb7e"