Exclude dev dependencies from version control.

This will ignore dependencies only installed as part of the dev setup.

.gitignore

@@ -80,5 +80,59 @@ composer.phar
 vendor/**/tests/
 vendor/**/Test/
 vendor/sabre/*/examples/
+
+# Exclude dev dependencies
+vendor/behat/
+vendor/bin/behat
+vendor/bin/pdepend
+vendor/bin/php-parse
+vendor/bin/phpcbf
+vendor/bin/phpcs
+vendor/bin/phpmd
+vendor/bin/phpunit
+vendor/bin/yaml-lint
+vendor/composer/pcre/
+vendor/composer/xdebug-handler/
+vendor/dms/
+vendor/doctrine/
+vendor/fabpot/
+vendor/myclabs/
+vendor/nikic/
+vendor/pdepend/
+vendor/phar-io/
+vendor/php-mock/
+vendor/phpmd/
+vendor/phpunit/
+vendor/psr/container/
+vendor/psr/event-dispatcher/
+vendor/sebastian/
+vendor/squizlabs/
+vendor/symfony/browser-kit/
+vendor/symfony/config/
+vendor/symfony/console/
+vendor/symfony/css-selector/
+vendor/symfony/dependency-injection/
+vendor/symfony/deprecation-contracts/
+vendor/symfony/dom-crawler/
+vendor/symfony/event-dispatcher-contracts/
+vendor/symfony/event-dispatcher/
+vendor/symfony/filesystem/
+vendor/symfony/http-client-contracts/
+vendor/symfony/http-client/
+vendor/symfony/mime/
+vendor/symfony/polyfill-ctype/
+vendor/symfony/polyfill-intl-grapheme/
+vendor/symfony/polyfill-intl-idn/
+vendor/symfony/polyfill-intl-normalizer/
+vendor/symfony/polyfill-mbstring/
+vendor/symfony/polyfill-php72/
+vendor/symfony/polyfill-php73/
+vendor/symfony/polyfill-php80/
+vendor/symfony/service-contracts/
+vendor/symfony/string/
+vendor/symfony/translation-contracts/
+vendor/symfony/translation/
+vendor/symfony/yaml/
+vendor/theseer/
 # /info is a directory containing site-specific HTML documents
 /info/