Bump version to 3.0

pyproject.toml

 [tool.poetry]
 name = "AlekSIS-App-Alsijil"
-version = "2.2.dev0"
+version = "3.0.dev0"
 packages = [
     { include = "aleksis" }
 ]
@@ -48,8 +48,8 @@ secondary = true
 
 [tool.poetry.dependencies]
 python = "^3.9"
-aleksis-core = "^2.12"
-aleksis-app-chronos = "^2.2"
+aleksis-core = "^3.0.dev3"
+aleksis-app-chronos = "^3.0.dev1"
 aleksis-app-stoelindeling = { version = "^1.0", optional = true }
 
 [tool.poetry.dev-dependencies]