Update .travis.yml

Merge pull request parse-community#431 from acinader/release-1.5.1

prep for release 1.5.1

Release 1.4.0 🐘 (parse-community#381)

* prepped for 1.4.0 release

* new additions to changelog

* adds verification emails & ParseConfig to README

* update README & test version to 1.4.0

* pull version from current sdk version

* Update parse-server-test to 1.3.6, pinning mongodb to v3.4

* Use mongodb 3.4 on prestart

Prep for 1.3.0 (parse-community#352)

Expanded Travis CI Tests (Curl/Non-Curl)

Updated parse-php-sdk to version 1.2.9

Bumped version to 1.2.8

Adds methods to ParsePushStatus to handle checking the current status…

… of a recent push request.

Modifies http_build_request to always use '&' to combine query args with

Helper for twitter auth added and general login/linkers added for fut…

…ure 3rd party auth