Unique indexes (#1971)

* Add unique indexing

* Add unique indexing for username/email

* WIP

* Finish unique indexes

* Notes on how to upgrade to 2.3.0 safely

* index on unique-indexes: c454180 Revert "Log objects rather than JSON stringified objects (#1922)"

* reconfigure username/email tests

* Start dealing with test shittyness

* Remove tests for files that we are removing

* most tests passing

* fix failing test

* Make specific server config for tests async

* Fix more tests

* fix more tests

* Fix another test

* fix more tests

* Fix email validation

* move some stuff around

* Destroy server to ensure all connections are gone

* Fix broken cloud code

* Save callback to variable

* no need to delete non existant cloud

* undo

* Fix all tests where connections are left open after server closes.

* Fix issues caused by missing gridstore adapter

* Update guide for 2.3.0 and fix final tests

* use strict

* don't use features that won't work in node 4

* Fix syntax error

* Fix typos

* Add duplicate finding command

* Update 2.3.0.md

spec/ParseInstallation.spec.js

@@ -5,13 +5,12 @@
 let auth = require('../src/Auth');
 let cache = require('../src/cache');
 let Config = require('../src/Config');
-let DatabaseAdapter = require('../src/DatabaseAdapter');
 let Parse = require('parse/node').Parse;
 let rest = require('../src/rest');
 let request = require("request");
 
 let config = new Config('test');
-let database = DatabaseAdapter.getDatabaseConnection('test', 'test_');
+let database = config.database;
 let defaultColumns = require('../src/Controllers/SchemaController').defaultColumns;
 
 const installationSchema = { fields: Object.assign({}, defaultColumns._Default, defaultColumns._Installation) };