Format SVG React snapshots as <svg> tag with props (facebook#5196)

* Format SVG React snapshots as <svg> tag with props

* Keep output simpler

Author: gaearon

config/jest/fileTransform.js

@@ -21,7 +21,15 @@ module.exports = {
       return `module.exports = {
         __esModule: true,
         default: ${assetFilename},
-        ReactComponent: () => ${assetFilename},
+        ReactComponent: (props) => ({
+          $$typeof: Symbol.for('react.element'),
+          type: 'svg',
+          ref: null,
+          key: null,
+          props: Object.assign({}, props, {
+            children: ${assetFilename}
+          })
+        }),
       };`;
     }