symfony 4.0 failed to install assetic-bundle

I'm trying this new symfony 4.0, so I failed to install assetic-bundle, the command I use

composer require assetic-bundle

I got a set of problems :

Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- symfony/assetic-bundle v2.8.2 requires symfony/framework-bundle ~2.3|~3.0
-> satisfiable by symfony/framework-bundle[2.3.x-dev, 2.4.x-dev,/....../  v3.4.0-RC2]
but these conflict with your requirements or minimum-stability.

I got four problems like this (I just took the important part of the first because they are very long) my requirements in the json file:

"require": {
    "php": "^7.1.3",
    "sensio/framework-extra-bundle": "^5.1",
    "sensiolabs/security-checker": "^4.1",
    "symfony/asset": "^4.0",
    "symfony/console": "^4.0",
    "symfony/flex": "^1.0",
    "symfony/framework-bundle": "^4.0",
    "symfony/lts": "^4@dev",
    "symfony/profiler-pack": "^1.0",
    "symfony/twig-bundle": "^4.0",
    "symfony/web-server-bundle": "^4.0",
    "symfony/yaml": "^4.0"
},
"require-dev": {
    "symfony/dotenv": "^4.0"
},

hearing from you, thanks ^_^