Sort imports and requires (#3056)

This will definitely save time, and ensure more uniformity.

It moves the `createServiceTester()` calls to a different place from where I'd like them, though I'm happy to have them checked by the linter.

Closes #2701

services/matrix/matrix.tester.js

@@ -1,7 +1,6 @@
 'use strict'
 
 const Joi = require('joi')
-
 const t = (module.exports = require('../tester').createServiceTester())
 
 t.create('get room state as guest')