Updates jest config for Junit files (#3067)

* Updates jest config

With this change, jest junit files will by default be written to /tmp . This behvaiour can be overridden by:

`JEST_JUNIT_OUTPUT_DIR=$DESIRED_DIRECTORY npm test`

* Formatting

assets/jest.config.js

@@ -133,6 +133,7 @@ module.exports = {
         classNameTemplate: '{classname}',
         titleTemplate: '{title}', // outputname
         includeConsoleOutput: true,
+        outputDirectory: '/tmp',
       },
     ],
   ],