Merge pull request #342 from cakephp/ADmad-patch-1

Upgrade to phpstan 0.9

.travis.yml

@@ -57,7 +57,7 @@ before_script:
   - if [[ $PREFER_LOWEST != 1 ]]; then composer install --no-interaction; fi
   - if [[ $PREFER_LOWEST = 1 ]]; then composer update --no-interaction --prefer-lowest; fi
 
-  - if [[ $PHPSTAN = 1 ]]; then composer require --dev phpstan/phpstan:^0.8; fi
+  - if [[ $PHPSTAN = 1 ]]; then composer require --dev phpstan/phpstan:^0.9; fi
 
   - if [[ $DB = 'mysql' ]]; then mysql -u root -e 'CREATE DATABASE cakephp_test DEFAULT COLLATE=utf8mb4_general_ci; CREATE DATABASE cakephp_comparisons;'; fi