Improve travis builds and test PHP 7.0 and HHVM (with allow failures)

.travis.yml

@@ -1,18 +1,28 @@
 language: php
 
-before_script:
-  - sudo apt-get update
-  - sudo apt-get install -y ffmpeg libavcodec-extra-53
-  - composer self-update
-  - composer install --no-interaction --prefer-source --dev
-
 php:
-  - 5.3.3
   - 5.3
   - 5.4
   - 5.5
   - 5.6
+  - 7.0
+  - hhvm
+
+matrix:
+  allow_failures:
+    - php: hhvm
+  include:
+    - php: 5.3
+      env: COMPOSER_FLAGS="--prefer-lowest"
+
+before_install:
+  - sudo apt-get update
+  - composer self-update
+  - if [ "$COMPOSER_FLAGS" == "--prefer-lowest" ]; then composer require "roave/security-advisories" dev-master --no-update; fi;
+
+install:
+  - sudo apt-get install -y ffmpeg libavcodec-extra-53
+  - composer update --prefer-source $COMPOSER_FLAGS
 
 script:
   - vendor/bin/phpunit --verbose
-  - vendor/bin/phpunit --verbose -c phpunit-functional.xml.dist

composer.json

@@ -22,7 +22,7 @@
         }
     ],
     "require": {
-        "php": ">=5.3.3",
+        "php": "^5.3.9 || ^7.0",
         "alchemy/binary-driver": "^1.5",
         "doctrine/cache": "^1.0",
         "evenement/evenement": "^2.0 || ^1.0",