test with and without phpredis extension

Author: chrisboulton

.travis.yml

@@ -2,5 +2,9 @@ language: php
 php:
   - 5.3
   - 5.4
+env:
+  - REDIS_STANDALONE=0
+  - REDIS_STANDALONE=1
 before_script:
+  - sh -c "if [ $REDIS_STANDALONE -eq 0 ]; then pecl install redis && echo \"extension=redis.so\" >> `php --ini | grep \"Loaded Configuration\" | sed -e \"s|.*:\s*||\"`; fi"
   - composer install --dev