Global test setup

Configure chai and SandboxedModule globally with options used in many
tests.

That required upgrading mocha and SandboxedModule.

services/document-updater/test/acceptance/js/GettingProjectDocsTests.js

@@ -12,9 +12,7 @@
  * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
  */
 const sinon = require('sinon')
-const chai = require('chai')
-chai.should()
-const { expect } = chai
+const { expect } = require('chai')
 
 const MockWebApi = require('./helpers/MockWebApi')
 const DocUpdaterClient = require('./helpers/DocUpdaterClient')