[WIP] Enable test suite to be randomized (#7265)

* initial run

* Update ParseGraphQLServer.spec.js

* temporarily enable reporter

* Bump retry limit

* fix undefined database

* try to catch error

* Handle LiveQueryServers

* Update Config.js

* fast-fail false

* Remove usage of AppCache

* oops

* Update contributing guide

* enable debugger, try network retry attempt 1

* Fix ldap unbinding

* move non specs to support

* add missing mock adapter

* fix Parse.Push

* RestController should match batch.spec.js

* Remove request attempt limit

* handle index.spec.js

* Update CHANGELOG.md

* Handle error: tuple concurrently updated

* test transactions

* Clear RedisCache after every test

* LoggerController.spec.js

* Update schemas.spec.js

* finally fix transactions

* fix geopoint deadlock

* transaction with clean database

* batch.spec.js

spec/support/MockLdapServer.js

@@ -0,0 +1,54 @@
+const ldapjs = require('ldapjs');
+const fs = require('fs');
+
+const tlsOptions = {
+  key: fs.readFileSync(__dirname + '/cert/key.pem'),
+  certificate: fs.readFileSync(__dirname + '/cert/cert.pem'),
+};
+
+function newServer(port, dn, provokeSearchError = false, ssl = false) {
+  const server = ssl ? ldapjs.createServer(tlsOptions) : ldapjs.createServer();
+
+  server.bind('o=example', function (req, res, next) {
+    if (req.dn.toString() !== dn || req.credentials !== 'secret')
+      return next(new ldapjs.InvalidCredentialsError());
+    res.end();
+    return next();
+  });
+
+  server.search('o=example', function (req, res, next) {
+    if (provokeSearchError) {
+      res.end(ldapjs.LDAP_SIZE_LIMIT_EXCEEDED);
+      return next();
+    }
+    const obj = {
+      dn: req.dn.toString(),
+      attributes: {
+        objectclass: ['organization', 'top'],
+        o: 'example',
+      },
+    };
+
+    const group = {
+      dn: req.dn.toString(),
+      attributes: {
+        objectClass: ['groupOfUniqueNames', 'top'],
+        uniqueMember: ['uid=testuser, o=example'],
+        cn: 'powerusers',
+        ou: 'powerusers',
+      },
+    };
+
+    if (req.filter.matches(obj.attributes)) {
+      res.send(obj);
+    }
+
+    if (req.filter.matches(group.attributes)) {
+      res.send(group);
+    }
+    res.end();
+  });
+  return new Promise(resolve => server.listen(port, () => resolve(server)));
+}
+
+module.exports = newServer;