Add CI job to test for latest sentry/sentry

Author: Jean85

.travis.yml

@@ -31,6 +31,8 @@ jobs:
         - composer remove --dev friendsofphp/php-cs-fixer phpstan/phpstan --no-update
         - travis_retry travis_wait composer install --no-interaction --prefer-dist
         - travis_retry travis_wait composer update --no-interaction --prefer-dist --prefer-stable --prefer-lowest
+    - name: sentry/sentry dev-develop
+      install: composer require sentry/sentry:dev-develop
     - stage: Code style and static analysis
       script:
         - composer phpstan