Optimize composer autoloader before deploying

This converts PSR-0/PSR-4 autoloading to classmap to get a faster autoloader (up to 20% performance increase)

.travis.yml

@@ -13,6 +13,7 @@ script:
 
 before_deploy:
   - composer install
+  - composer dump-autoload --optimize
   - tar -czf "pico-release-$TRAVIS_TAG.tar.gz" .htaccess README.md CHANGELOG.md CONTRIBUTING.md composer.json composer.lock LICENSE config content-sample lib plugins themes vendor index.php
 
 deploy: