add travis

.travis.yml

@@ -0,0 +1,12 @@
+language: php
+php:
+  - '5.2'
+  - '5.3'
+  - '5.4'
+  - '5.6'
+matrix:
+  include:
+    - php: 5.2
+      dist: precise
+    - php: 5.3
+      dist: precise