feature #107 Add support for PHP 7.4 (pamil)

This PR was merged into the 2.1-dev branch.

Discussion
----------



Commits
-------

c3488f08d6 Add support for PHP 7.4

.travis.yml

@@ -4,6 +4,7 @@ php:
     - '7.1'
     - '7.2'
     - '7.3'
+    - '7.4'
 
 env:
     - SYMFONY_VERSION=3.4.*

composer.json

@@ -12,7 +12,7 @@
     ],
     "require": {
         "php": "^7.1",
-        "behat/behat": "^3.4",
+        "behat/behat": "^3.6.1",
         "symfony/dependency-injection": "^3.4|^4.4|^5.0",
         "symfony/http-kernel": "^3.4|^4.4|^5.0",
         "symfony/proxy-manager-bridge": "^3.4|^4.4|^5.0"