No need to update composer in Travis tests

Author: amacneil

.travis.yml

@@ -13,8 +13,6 @@ env:
   - SYMFONY_VERSION="2.*" GUZZLE_VERSION="3.*"
 
 before_script:
-  - composer self-update
-  - composer --version
   - composer require symfony/http-foundation:${SYMFONY_VERSION} --no-update
   - composer require guzzle/http:${GUZZLE_VERSION} --no-update
   - composer install -n --dev --prefer-source