up deps, up minimal php version to 7.4

Author: alexpts

.travis.yml

@@ -1,7 +1,7 @@
 sudo: false
 language: php
 php:
-  - 7.2
+  - 7.4
 
 before_script:
   - composer self-update

composer.json

@@ -15,10 +15,10 @@
     }],
     "minimum-stability": "stable",
     "require": {
-        "php": "~7.2",
-        "symfony/dependency-injection": "^4.2",
-        "symfony/yaml": "^4.2",
-        "symfony/config": "^4.2"
+        "php": "~7.4",
+        "symfony/dependency-injection": "~5.0",
+        "symfony/yaml": "^5.0",
+        "symfony/config": "^5.0"
     },
     "autoload": {
         "psr-0": {
@@ -31,7 +31,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.5",
+        "phpunit/phpunit": "^8.4",
         "mikey179/vfsStream": "^1.6"
     }
 }