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

spec/.eslintrc.json

@@ -25,7 +25,8 @@
       "jequal": true,
       "create": true,
       "arrayContains": true,
-      "expectAsync": true
+      "expectAsync": true,
+      "databaseAdapter": true
     },
     "rules": {
       "no-console": [0],