Examine worker/memory in CI (#2087)

playbook/jest.config.js

@@ -71,7 +71,7 @@ module.exports = {
   // globals: {},
 
   // The maximum amount of workers used to run your tests. Can be specified as % or a number. E.g. maxWorkers: 10% will use 10% of your CPU amount + 1 as the maximum worker number. maxWorkers: 2 will use a maximum of 2 workers.
-  // maxWorkers: "50%",
+  maxWorkers: "2",
 
   // An array of directory names to be searched recursively up from the requiring module's location
   moduleDirectories: [