Postgres adapter (#2012)

* Remove adaptiveCollection

* Remove an adaptiveCollection use

* Remove an adaptiveCollection

* make adaptiveCollection private

* Remove collection from mongoadapter

* Move schema collection usage into mongo adapter

* stop relying on mongo format for removing join tables

* reduce usage of schemaCollection

* remove uses of _collection

* Move CLP setting into mongo adapter

* remove all uses of schemaCollection

* make schemaCollection private

* remove transform from schemaCollection

* rename some stuff

* Tweak paramaters and stuff

* reorder some params

* reorder find() arguments

* finishsh touching up argument order

* Accept a database adapter as a parameter

* First passing test with postgres!

* Actually use the provided className

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

* Start dealing with test shittyness

* Make specific server config for tests async

* Fix email validation

* Fix broken cloud code

* Save callback to variable

* undo

* Fix tests

* Setup travis

* fix travis maybe

* try removing db user

* indentation?

* remove postgres version setting

* sudo maybe?

* use postgres username

* fix check for _PushStatus

* excludes

* remove db=mongo

* allow postgres to fail

* Fix allow failure

* postgres 9.4

* Remove mongo implementations and fix test

* Fix test leaving behind connections

package.json

@@ -38,6 +38,7 @@
     "parse-server-push-adapter": "^1.0.0",
     "parse-server-s3-adapter": "^1.0.1",
     "parse-server-simple-mailgun-adapter": "^1.0.0",
+    "pg-promise": "^4.4.0",
     "redis": "^2.5.0-1",
     "request": "^2.65.0",
     "request-promise": "^3.0.0",