travis: drop unused commands

.travis.yml

@@ -1,5 +1,7 @@
 language: php
+
 dist: trusty
+
 php:
   - 7.0
   - 7.1
@@ -14,14 +16,12 @@ cache:
   directories:
     - $HOME/.composer/cache
 
-script:
-  - vendor/bin/phpunit --coverage-clover=coverage.clover -v
-  - composer update --no-interaction --prefer-source
-  - vendor/bin/phpunit -v
-
 before_script:
   - composer install --no-interaction
 
+script:
+  - vendor/bin/phpunit --coverage-clover=coverage.clover -v
+
 after_script:
   - wget https://scrutinizer-ci.com/ocular.phar
   - php ocular.phar code-coverage:upload --format=php-clover coverage.clover