Refactor travis.yml

Fix php-worker build fail

fix install hhvm package cannot be authenticated

Fix workspace php56 build fail

fix aerospike build fail

Add LDAP support to PHP 5.6 workspace

Issue #1296:
PHP 7.0 and 7.1 workspaces support adding the PHP LDAP module. The
PHP 5.6 workspace file seems to have missed this for some reason.

LInk is not working

Compatibility for COMPOSE_FILE

Don't use docker-compose down to stop containers

#1275 Fix memory leaks in docker-sync with verbose true

adding '\' to the Dockerfile nginx statement

Clarified how to split multiple docker-compose files on Windows

Remove duplicate configuration

COMPOSE_PATH_SEPARATOR
If set, the value of the COMPOSE_FILE environment variable will be separated using this character as path separator.

This delete containers and volume too. 
Use docker-compose stop who only stop containers

* opencollective-opencollective:
  add open collective to the readme
  Update README.md

Merge branch 'opencollective' of https://github.com/opencollective/laradock into opencollective-opencollective

* 'opencollective' of https://github.com/opencollective/laradock:
  Update README.md

Set environment to change source.

Specifying included docker-compose files in the .env is more flexible

Specifying included docker-compose files in the .env is more flexible than hardcoding in the shell script.