Composer error when updating symfony

I'm trying to update symfony from version 2.3 to a more advanced one, my intention was about a 3.0 but there's no way.

Reading in the forums I updated the composer.json to a "minimum-stability": "dev" but even so, I always get some dependency error. I also say that I do not know what many of them are for, that I only know how to use php, symfony and doctrine I leave here my composer.json

   "require": {
    "php": ">=5.3.3",
    "symfony/symfony": ">3.0",
    "doctrine/orm": ">=2.2.3",
    "doctrine/doctrine-bundle": ">1.6",
    "twig/extensions": ">1.0",
    "symfony/assetic-bundle": ">2.8",
    "symfony/swiftmailer-bundle": ">2.3",
    "symfony/monolog-bundle": ">2.3",
    "sensio/distribution-bundle": ">2.3",
    "sensio/framework-extra-bundle": ">2.3",
    "sensio/generator-bundle": ">2.3",
    "incenteev/composer-parameter-handler": ">2.0"
},
"scripts": {
    "post-install-cmd": [
        "Incenteev\ParameterHandler\ScriptHandler::buildParameters",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::buildBootstrap",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::installAssets",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::installRequirementsFile"
    ],
    "post-update-cmd": [
        "Incenteev\ParameterHandler\ScriptHandler::buildParameters",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::buildBootstrap",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::installAssets",
        "Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::installRequirementsFile"
    ]
},
"config": {
    "bin-dir": "bin"
},
"minimum-stability": "dev",
"extra": {
    "symfony-app-dir": "app",
    "symfony-web-dir": "web",
    "incenteev-parameters": {
        "file": "app/config/parameters.yml"
    },
    "branch-alias": {
        "dev-master": "2.3-dev"
    }
}

}

Dependency error

  

root @ symfony2: / var / www / html / Symfony # composer update symfony / symfony   Loading composer repositories with package information Updating   dependencies (including require-dev) Your requirements could not be   resolved to an installable set of packages. Problem 1       - The requested package doctrine / doctrine-bundle (locked at v1.2.0, required as & 1.6) is satisfiable by   doctrine / doctrine-bundle [v1.2.0] but these conflict with your   requirements or minimum-stability. Problem 2       - The requested package twig / extensions (locked at v1.0.0, required as > 1.0) is satisfiable by twig / extensions [v1.0.0] but these   conflict with your requirements or minimum-stability. Problem 3       - The requested package symfony / assetic-bundle (locked at v2.3.0, required as > 2.8) is satisfiable by symfony / assetic-bundle [v2.3.0] but   these conflict with your requirements or minimum-stability. Problem   4       - The requested package symfony / monolog-bundle (locked at v2.3.0, required as > 2.3) is satisfiable by symfony / monolog-bundle [v2.3.0] but   these conflict with your requirements or minimum-stability. Problem   5       - The requested package incenteev / composer-parameter-handler (locked at v2.0.0, required as > 2.0) is satisfiable by   incenteev / composer-parameter-handler [v2.0.0] but these conflict with   your requirements or minimum-stability. Problem 6       - symfony / symfony dev-master requires php ^ 7.1.3 - > your PHP version (5.5.9) does not satisfy that requirement.       - symfony / symfony 4.0.x-dev requires php ^ 7.1.3 - > your PHP version (5.5.9) does not satisfy that requirement.       - Conclusion: do not install symfony / symfony 3.4.x-dev       - Conclusion: do not install symfony / symfony 3.3.x-dev

I do not have much experience, it has only occurred to me that I can install the same packages in a virtual one and then take the composer.json and take it as a reference, so it supposedly will not have incompatibilities.

any help will be welcome

If I put master I get this:

  

Problem 1       - The requested package doctrine / doctrine-bundle (locked at v1.2.0, required as> 1.6) is satisfiable by doctrine / doctrine-bundle [v1.2.0] but these conflicts with your requirements or minimum-stability.     Problem 2       - The requested package twig / extensions (locked at v1.0.0, required as > 1.0) is satisfiable by twig / extensions [v1.0.0] but these conflicts with your requirements or minimum-stability.     Problem 3       - The requested package symfony / assetic-bundle (locked at v2.3.0, required as> 2.8) is satisfiable by symfony / assetic-bundle [v2.3.0] but these conflicts with your requirements or minimum-stability.     Problem 4       - The requested package symfony / monolog-bundle (locked at v2.3.0, required as > 2.3) is satisfiable by symfony / monolog-bundle [v2.3.0] but these conflicts with your requirements or minimum-stability.     Problem 5       - The requested package incenteev / composer-parameter-handler (locked at v2.0.0, required as > 2.0) is satisfiable by incenteev / composer-parameter-handler [v2.0.0] but these conflicts with your requirements or minimum-stability.     Problem 6       - Installation request for symfony / symfony master - > satisfiable by symfony / symfony [dev-master].       - symfony / symfony dev-master requires php ^ 7.1.3 - > your PHP version (5.5.9) does not satisfy that requirement.