Use install_dev.sh for Travis

Add `--no-dev` to `composer install` for prod env

.travis.yml

@@ -91,8 +91,8 @@ before_install:
     - if [[ $TRAVIS_REPO_SLUG = wallabag/wallabag ]]; then cp .composer-auth.json ~/.composer/auth.json; fi;
 
 script:
-    - travis_wait bash install.sh
+    - travis_wait bash install_dev.sh
     - ant prepare-$DB
-    - phpunit -v
+    - if [[ $VALIDATE_TRANSLATION_FILE = '' ]]; then phpunit -v ; fi;
     - if [[ $CS_FIXER = run ]]; then php bin/php-cs-fixer fix src/ --verbose --dry-run ; fi;
     - if [[ $VALIDATE_TRANSLATION_FILE = run ]]; then php bin/console lint:yaml src/Wallabag/CoreBundle/Resources/translations -v ; fi;