minor #1152 Updated backend dependencies (javiereguiluz)

This PR was squashed before being merged into the master branch.

Discussion
----------

Updated backend dependencies

Dependencies were updated with Composer 2 RC1.

Commits
-------

8a3ac44 Updated backend dependencies

Author: javiereguiluz

.php_cs.dist

@@ -20,7 +20,7 @@ $finder = PhpCsFixer\Finder::create()
     ->notPath('public/index.php')
 ;
 
-return PhpCsFixer\Config::create()
+return (new PhpCsFixer\Config())
     ->setRiskyAllowed(true)
     ->setRules([
         '@Symfony' => true,

.travis.yml

@@ -20,7 +20,7 @@ env:
     # the same directory as the simple-phpunit if it is not provided. It's also possible to set
     # this env var in the phpunit.xml.dist file.
     - SYMFONY_PHPUNIT_DIR=./bin/.phpunit
-    - SYMFONY_DEPRECATIONS_HELPER=9
+    - SYMFONY_DEPRECATIONS_HELPER=6
     - ACTION="install"
     # Add the Symfony binary's path to PATH.
     - PATH="$HOME/.symfony/bin:$PATH"
@@ -35,16 +35,13 @@ jobs:
   include:
     # Run tests with the dependencies from composer.lock
     - php: 7.2
-    - php: 7.3
     - php: 7.4
-
-    # Run tests against dev (currently 5.1.x-dev)
-    - php: 7.3
-      env: STABILITY=dev ACTION=update
-
+    - php: nightly
     # Run tests against dev-master (currently 5.2.x-dev)
-    - php: 7.3
+    - php: 7.4
       env: STABILITY=dev SYMFONY=5.* ACTION=update
+  allow_failures:
+     - php: nightly
 
 before_install:
   - phpenv config-rm xdebug.ini || true

composer.json

@@ -14,7 +14,7 @@
         "ext-pdo_sqlite": "*",
         "composer/package-versions-deprecated": "^1.8",
         "doctrine/doctrine-bundle": "^1.12|^2.0",
-        "doctrine/doctrine-migrations-bundle": "^1.3|^2.0",
+        "doctrine/doctrine-migrations-bundle": "^3.0",
         "doctrine/orm": "^2.5.11",
         "erusev/parsedown": "^1.6",
         "sensio/framework-extra-bundle": "^5.1",