minor #36647 Execute docker dependent tests with github actions (jakzal)

This PR was merged into the 4.4 branch.

Discussion
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Execute docker dependent tests with github actions

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | Fixes #36427
| License       | MIT
| Doc PR        | -

* redis, memcached, rabbitmq and vulcain dependent tests moved to the github action
* run on PHP 7.1 and 7.4 only
* use the `integration` group for all tests that depend on docker services
* do not exclude the `integration` group on Travis, but make sure tests that depend on docker services are skipped properly

[<img width="1222" alt="image" src="https://user-images.githubusercontent.com/190447/80806323-48339100-8bb2-11ea-95cd-5ce773c74ce6.png">](https://github.com/jakzal/symfony/runs/636461875?check_suite_focus=true)

Commits
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d710c1b654 Execute docker dependent tests with github actions

Author: fabpot

Tests/Functional/CachePoolsTest.php

@@ -26,9 +26,12 @@ public function testCachePools()
 
     /**
      * @requires extension redis
+     * @group integration
      */
     public function testRedisCachePools()
     {
+        $this->skipIfRedisUnavailable();
+
         try {
             $this->doTestCachePools(['root_config' => 'redis_config.yml', 'environment' => 'redis_cache'], RedisAdapter::class);
         } catch (\PHPUnit\Framework\Error\Warning $e) {
@@ -51,9 +54,12 @@ public function testRedisCachePools()
 
     /**
      * @requires extension redis
+     * @group integration
      */
     public function testRedisCustomCachePools()
     {
+        $this->skipIfRedisUnavailable();
+
         try {
             $this->doTestCachePools(['root_config' => 'redis_custom_config.yml', 'environment' => 'custom_redis_cache'], RedisAdapter::class);
         } catch (\PHPUnit\Framework\Error\Warning $e) {
@@ -121,4 +127,13 @@ protected static function createKernel(array $options = []): KernelInterface
     {
         return parent::createKernel(['test_case' => 'CachePools'] + $options);
     }
+
+    private function skipIfRedisUnavailable()
+    {
+        try {
+            (new \Redis())->connect(getenv('REDIS_HOST'));
+        } catch (\Exception $e) {
+            self::markTestSkipped($e->getMessage());
+        }
+    }
 }