Add travis YML file

Author: behzadsh

.travis.yml

@@ -0,0 +1,18 @@
+language: php
+php:
+  - 5.3
+  - 5.4
+  - 5.5
+  - 5.6
+  - 7.0
+  - hhvm
+
+matrix:
+    allow_failures:
+        - php: 7.0
+
+sudo: false
+
+install: travis_retry composer install --no-interaction --prefer-source
+
+script: vendor/bin/phpunit