Merge branch 'release/3.4.3'

* release/3.4.3:
  Composer update
  Composer installation step
  Added installation options for stability
  Allow failure for PHP 7.2
  Update PHP versions

.travis.yml

@@ -2,13 +2,27 @@ language: php
 
 php:
   - 5.6
-  - 7.0
+  - 7.0.21
   - 7.1
+  - 7.2
+
+env:
+  global:
+    - setup=basic
+
+matrix:
+  allow_failures:
+    - php: 7.2
+  fast_finish: true
+  include:
+    - php: 5.6
+      env: setup=lowest
+    - php: 5.6
+      env: setup=stable
 
 before_install:
-  - if [[ $TRAVIS_PHP_VERSION != 7.1 ]] ; then phpenv config-rm xdebug.ini; fi
+  - if [[ $TRAVIS_PHP_VERSION != 7.2 ]] ; then phpenv config-rm xdebug.ini; fi
   - mv .env.example .env
-  - travis_retry composer self-update
 
 install:
   - composer install