Postgres: Operations, Hooks, OAuth login, Files support (#2528)

* Adds files related tests through fs-adapter with PG

* Schema deletions implementations

* Adds Hooks spec

* Fix test

* Adds support for containsAll (numbers and strings)

* Better support for deleteFields and deleteClass

* Recursive JSON update for authData

* Adds node_modules to travis cache

* Disable temporarily to make tests pass

* Adds _perishable_token support for _User class

* ignore when a table creation fails at init (table exists)

* Adds support for AddUnique and Remove

* PG 9.4 compatible functions

* Re-enable tests

* nit

* Better handling of schema creation race

spec/ValidationAndPasswordsReset.spec.js

@@ -187,7 +187,7 @@ describe("Custom Pages, Email Verification, Password Reset", () => {
     });
   });
 
-  it_exclude_dbs(['postgres'])('does send with a simple adapter', done => {
+  it('does send with a simple adapter', done => {
     var calls = 0;
     var emailAdapter = {
       sendMail: function(options){
@@ -675,7 +675,7 @@ describe("Custom Pages, Email Verification, Password Reset", () => {
     });
   });
 
-  it_exclude_dbs(['postgres'])('should send a password reset link', done => {
+  it('should send a password reset link', done => {
     var user = new Parse.User();
     var emailAdapter = {
       sendVerificationEmail: () => Promise.resolve(),
@@ -740,7 +740,7 @@ describe("Custom Pages, Email Verification, Password Reset", () => {
     });
   });
 
-  it_exclude_dbs(['postgres'])('should programatically reset password', done => {
+  it('should programatically reset password', done => {
     var user = new Parse.User();
     var emailAdapter = {
       sendVerificationEmail: () => Promise.resolve(),