Update common dependency constraints

Require contao/core-bundle ^4.4.8
Require contao-community-alliance/dc-general ^2.1.0
Require contao/manager-plugin ^2.1 for dev
Update constraint menatwork/contao-multicolumnwizard-bundle to ^3.4 for dev
Remove contao/manager-bundle from dev

Author: MiniModel

composer.json

@@ -33,15 +33,15 @@
   },
   "require": {
     "php": "^7.1",
-    "contao-community-alliance/dc-general": "^2.1@dev",
-    "contao/core-bundle": "^4.4",
+    "contao-community-alliance/dc-general": "^2.1.0",
+    "contao/core-bundle": "^4.4.8",
     "metamodels/core": "~2.1@dev",
     "symfony/dependency-injection": "^3.3 || ^4.0",
     "symfony/http-kernel": "^3.3 || ^4.0"
   },
   "require-dev": {
-    "contao/manager-bundle": "^4.4",
-    "menatwork/contao-multicolumnwizard-bundle": "^3.4.0@beta",
+    "contao/manager-plugin": "^2.1",
+    "menatwork/contao-multicolumnwizard-bundle": "^3.4",
     "phpcq/all-tasks": "^1.2"
   },
   "autoload": {