Drop unmaintained Symfony versions support (#228)

Author: norkunas

composer.json

@@ -14,13 +14,13 @@
     "php": "^7.0",
     "willdurand/geocoder": "^4.0",
     "geocoder-php/plugin": "^1.0",
-    "symfony/framework-bundle": "^3.3 || ^4.0",
-    "symfony/options-resolver": "^3.3 || ^4.0",
-    "symfony/console": "^3.3 || ^4.0"
+    "symfony/framework-bundle": "^3.4 || ^4.2",
+    "symfony/options-resolver": "^3.4 || ^4.2",
+    "symfony/console": "^3.4 || ^4.2"
   },
   "require-dev": {
     "symfony/phpunit-bridge": "^4.3",
-    "symfony/yaml": "^3.3 || ^4.0",
+    "symfony/yaml": "^3.4 || ^4.2",
     "geoip/geoip": "~1.17",
     "doctrine/cache": "~1.3",
     "doctrine/orm": "~2.3",
@@ -52,7 +52,7 @@
     "geocoder-php/maxmind-provider": "^4.0",
     "geocoder-php/mapzen-provider": "^4.0",
     "geocoder-php/mapquest-provider": "^4.0",
-    "symfony/validator": "^3.3 || ^4.0"
+    "symfony/validator": "^3.4 || ^4.2"
   },
   "conflict":  {
     "willdurand/geocoder": "3.2",