Make sure that test stuff doesn't end up in bundles

Summary: When bundling a production bundle of flipper-ui / flipper-server, noticed that a lot of irrelevant stuff ends up. Like: `jest`, `metro`, `testing-library`. The whole jungle basically. Will add safety checks in the next diffs that this no longer happens

Reviewed By: passy

Differential Revision: D33186531

fbshipit-source-id: 1e2034153c8c4a3fac02cd9ce27d99224223df7a

desktop/scripts/jest-setup.ts

@@ -11,6 +11,9 @@
 // eslint-disable-next-line
 global.fetch = require('jest-fetch-mock');
 
+// @ts-ignore
+global.electronRequire = require;
+
 // make sure test run everywhere in the same timezone!
 // +11, somewhere in the middle of nowhere, so this deviates for everyone and will fail early :)
 const timezone = 'Pacific/Pohnpei';