run a Travis build with the lowest possible deps

Author: xabbuh

.travis.yml

@@ -1,5 +1,9 @@
 language: php
 
+env:
+  global:
+    - deps=""
+
 php:
   - 5.3
   - 5.4
@@ -11,11 +15,15 @@ php:
 
 matrix:
   fast_finish: true
+  include:
+    - php: 5.3
+      env: deps="low"
   allow_failures:
     - php: hhvm-nightly
 
 install:
-  - composer install
+  - if [ "$deps" = "low" ]; then composer update --prefer-lowest --prefer-stable; fi
+  - if [ "$deps" = "" ]; then composer install; fi
 
 script:
   - phpunit --coverage-clover=coverage.clover