Added lock file to ignore

Author: lucasantarella

.travis.yml

@@ -1,6 +1,5 @@
 language: php
 php:
-  - 5.3
   - 5.4
   - 5.5
   - 5.6
@@ -10,4 +9,4 @@ php:
   - nightly
 
 install:
-  - composer install --no-interaction
+  - composer install --no-interaction --dev