try to fix travis

Author: dominikzogg

.travis.yml

@@ -87,24 +87,23 @@ matrix:
     - php: 7.4
       env: phpunit=~8.5.0
     - php: 7.3
-      env: phpunit=^9.0@dev phpunit/php-invoker:^3.0@dev
+      env: phpunit=^9.0@dev phpinvoker=^3.0@dev
     - php: 7.4
-      env: phpunit=^9.0@dev phpunit/php-invoker:^3.0@dev
+      env: phpunit=^9.0@dev phpinvoker=^3.0@dev
 
   allow_failures:
     - php: 7.3
-      env: phpunit=^9.0@dev phpunit/php-invoker:^3.0@dev
+      env: phpunit=^9.0@dev phpinvoker=^3.0@dev
     - php: 7.4
-      env: phpunit=^9.0@dev phpunit/php-invoker:^3.0@dev
-
+      env: phpunit=^9.0@dev phpinvoker=^3.0@dev
 
 before_script:
   - echo 'extension=apcu.so' >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/apcu.ini
   - echo 'Europe/Zurich' | sudo tee /etc/timezone
   - echo 'date.timezone = "Europe/Zurich"' >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
   - composer self-update -q
   - composer global require hirak/prestissimo
-  - composer require phpunit/phpunit:${phpunit}
+  - if [ -z "$phpinvoker" ]; then composer require phpunit/phpunit:${phpunit}; else composer require phpunit/phpunit:${phpunit} phpunit/php-invoker:${phpinvoker}; fi
 
 script:
   - composer test