another attempt with firebird

.travis.yml

@@ -10,8 +10,11 @@ php:
   - hhvm
   - nightly
 
-install:
+before_install:
+  - sudo apt-get update
   - sudo apt-get install -qq php5-interbase firebird2.5-superclassic
+
+install:
   - sudo dpkg-reconfigure firebird2.5-superclassic
 
 before_script:
@@ -26,3 +29,7 @@ script:
 after_script:
     - wget https://scrutinizer-ci.com/ocular.phar
     - php ocular.phar code-coverage:upload --format=php-clover build/logs/clover.xml
+
+matrix:
+  allow_failures:
+    - php: 5.3