Use dev HTTP-Kernel so we can generate code coverage again.

An error with the test container will be coming to 4.4.1 (which is not released yet). When it is available we should revert the changes to composer.json.

.travis.yml

@@ -12,7 +12,6 @@ php:
   - '7.2'
   - '7.3'
   - '7.4snapshot'
- # - 'nightly'
 
 install:
   - composer install
@@ -27,8 +26,7 @@ install:
   - mysql -e "SET GLOBAL FOREIGN_KEY_CHECKS=1;"
 
 script:
-  #- php bin/phpunit --coverage-clover=coverage.xml
-  - php bin/phpunit
+  - php bin/phpunit --coverage-clover=coverage.xml
   # Perform some simple linting if everything is correct
   - ./bin/console lint:yaml config --parse-tags
   - ./bin/console lint:twig templates --env=prod
@@ -42,7 +40,4 @@ after_success:
   - bash <(curl -s https://codecov.io/bash)
 
 matrix:
-  fast_finish: true
-  allow_failures:
-    - php: 7.4snapshot
-   # - php: nightly
+  fast_finish: true