minor #768 update dama/doctrine-test-bundle to ^5.0 (dmaicher)

This PR was squashed before being merged into the master branch (closes #768).

Discussion
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update dama/doctrine-test-bundle to ^5.0

Upgrades `dama/doctrine-test-bundle` to latest version which is compatible with PHPUnit 7 as well.

Updated travis config to not use legacy PHPUnit 5 anymore.

Commits
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f1f53a6 update dama/doctrine-test-bundle to ^5.0

Author: javiereguiluz

.travis.yml

@@ -9,6 +9,7 @@ cache:
 env:
   global:
     - SYMFONY_PHPUNIT_DIR="$HOME/symfony-bridge/.phpunit"
+    - SYMFONY_PHPUNIT_VERSION="6.3"
 
 matrix:
   fast_finish: true

composer.json

@@ -31,7 +31,7 @@
         "white-october/pagerfanta-bundle": "^1.1"
     },
     "require-dev": {
-        "dama/doctrine-test-bundle": "^4.0",
+        "dama/doctrine-test-bundle": "^5.0",
         "friendsofphp/php-cs-fixer": "^2.7",
         "symfony/browser-kit": "^4.0",
         "symfony/css-selector": "^4.0",