Fix unbound version constraints and update dependencies

Author: rosier

.travis.yml

@@ -57,4 +57,4 @@ script:
   - ./bin/console doctrine:schema:validate --skip-sync -vvv --no-interaction
   #  Fail CI if the repo is in a dirty state after building assets (only for current release ie install)
   #-  if [[ "$ACTION" == "install" ]]; then yarn install && yarn encore production && git add --all && git diff --staged --exit-code; fi
-  - composer validate
+  - composer validate --strict

composer.json

@@ -20,10 +20,10 @@
         "symfony/asset": "5.0.*",
         "symfony/console": "5.0.*",
         "symfony/dotenv": "5.0.*",
-        "symfony/expression-language": "*",
+        "symfony/expression-language": "5.0.*",
         "symfony/flex": "^1.1",
         "symfony/form": "5.0.*",
-        "symfony/framework-bundle": "*",
+        "symfony/framework-bundle": "5.0.*",
         "symfony/intl": "5.0.*",
         "symfony/mailer": "5.0.*",
         "symfony/monolog-bundle": "^3.1",