[tests] move helpers require into mocha opts - makes them available in the module scope

bridge/e2e/init.js

@@ -1,6 +1,5 @@
 const detox = require('detox');
 const config = require('../package.json').detox;
-require('./../helpers');
 
 before(async () => {
   await detox.init(config);

bridge/e2e/mocha.opts

@@ -4,3 +4,4 @@
 --bail
 --exit
 --require bridge/platform/node
+--require ./helpers