Update travis

- add cache on vendors
- try hhvm
- update composer

Author: j0k3r

.travis.yml

@@ -1,15 +1,36 @@
 language: php
 
 php:
-  - 5.3
-  - 5.4
-  - 5.5
-  - 5.6
+    - 5.3
+    - 5.4
+    - 5.5
+    - 5.6
+    - nightly
+    - hhvm
+
+# run build against nightly but allow them to fail
+matrix:
+    fast_finish: true
+    allow_failures:
+        - php: nightly
+        - php: hhvm
+
+# faster builds on new travis setup not using sudo
+sudo: false
+
+# cache vendor dirs
+cache:
+    directories:
+        - lib/vendor
+        - $HOME/.composer/cache
+
+install:
+    - composer self-update
 
 before_script:
-  - sh -c 'if [ $(php -r "echo PHP_MINOR_VERSION;") -le 4 ]; then echo "extension = apc.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;'
-  - composer install
+    - sh -c 'if [ $(php -r "echo PHP_MINOR_VERSION;") -le 4 ]; then echo "extension = apc.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;'
+    - composer install
 
 script:
-  - php data/bin/check_configuration.php
-  - php -dshort_open_tag=Off -dmagic_quotes_gpc=Off data/bin/symfony symfony:test --trace
+    - php data/bin/check_configuration.php
+    - php -dshort_open_tag=Off -dmagic_quotes_gpc=Off data/bin/symfony symfony:test --trace