Added .travis.yml file

.travis.yml

@@ -0,0 +1,15 @@
+language: php
+
+php:
+  - '5.4'
+  - '5.5'
+  - '5.6'
+  - '7.0'
+  - hhvm
+  - nightly
+
+before_script:
+  - composer install --dev --prefer-source
+
+script:
+- vendor/bin/phpunit --coverage-text