Batch transaction (#5849)

* Batch transaction boilerplate

* Refactoring transaction boilerplate

* Independent sessions test

* Transactions - partial

* Missing only one test

* All tests passing for mongo db

* Tests on Travis

* Transactions on postgres

* Fix travis to restart mongodb

* Remove mongodb service and keep only mongodb runner

* MongoDB service back

* Initialize replicaset

* Remove mongodb runner again

* Again only with mongodb-runner and removing cache

* Trying with pretest and posttest

* WiredTiger

* Pretest and posttest again

* Removing inexistent scripts

* wiredTiger

* One more attempt

* Trying another way to run mongodb-runner

* Fixing tests

* Include batch transaction on direct access

* Add tests to direct access

.travis.yml

@@ -1,7 +1,6 @@
 language: node_js
 dist: trusty
 services:
-- mongodb
 - postgresql
 - redis-server
 - docker
@@ -19,13 +18,12 @@ branches:
 cache:
   directories:
   - "$HOME/.npm"
-  - "$HOME/.mongodb/versions"
 stage: test
 env:
   global:
   - COVERAGE_OPTION='./node_modules/.bin/nyc'
   matrix:
-  - MONGODB_VERSION=4.0.4
+  - MONGODB_VERSION=4.0.4 MONGODB_TOPOLOGY=replicaset MONGODB_STORAGE_ENGINE=wiredTiger
   - MONGODB_VERSION=3.6.9
   - PARSE_SERVER_TEST_DB=postgres
   - PARSE_SERVER_TEST_CACHE=redis
@@ -42,7 +40,6 @@ before_script:
 - psql -c 'create database parse_server_postgres_adapter_test_database;' -U postgres
 - psql -c 'CREATE EXTENSION postgis;' -U postgres -d parse_server_postgres_adapter_test_database
 - psql -c 'CREATE EXTENSION postgis_topology;' -U postgres -d parse_server_postgres_adapter_test_database
-- silent=1 mongodb-runner --start
 - greenkeeper-lockfile-update
 script:
 - npm run lint