add a config file for Travis CI

Author: xabbuh

.travis.yml

@@ -0,0 +1,30 @@
+sudo: false
+
+language: php
+
+cache:
+  directories:
+    - $HOME/.composer/cache/files
+
+php:
+  - 5.4
+  - 5.5
+  - 5.6
+  - 7.0
+  - hhvm
+
+matrix:
+  fast_finish: true
+  include:
+    - php: 5.3
+      env: deps="low"
+
+before_install:
+  - if [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then phpenv config-rm xdebug.ini; fi
+  - composer self-update
+
+install:
+  - if [[ "$deps" = "low" ]]; then composer update --prefer-lowest; else composer install; fi
+
+script:
+  - php validate.php