Composer message: requirements could not be resolved – SEO

Im trying to update symfony via composer.
I resolved most of the issues in my package, but cant seem to resolve this.
This error is just not making sense to me.

If anyone can help, would be great!

    Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - The requested package sonata-project/notification-bundle (installed at 2.3.0, required as 3.1.0) is satisfiable by sonata-project/notification-bundle[2.3.0] but these conflict with your requirements or minimum-stability.
  Problem 2
    - Installation request for jms/security-extra-bundle 1.6.1 -> satisfiable by jms/security-extra-bundle[1.6.1].
    - Can only install one of: jms/security-extra-bundle[1.6.1, 1.5.x-dev].
    - Installation request for jms/security-extra-bundle (installed at 1.5.x-dev, required as 1.6.1) -> satisfiable by jms/security-extra-bundle[1.5.x-dev].

Here are the required packages:

"require": {
    "php": ">=5.3.3",
    "symfony/icu": "1.1.0",
    "symfony/symfony": "2.8.*",
    "symfony/assetic-bundle": "~2.6",
    "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.*",

    "liip/theme-bundle": "1.2.*@dev",

    "incenteev/composer-parameter-handler": "~2.0",
    "friendsofsymfony/rest-bundle": "~1.5",
    "friendsofsymfony/user-bundle": "2.0.*@dev",
    "pugx/multi-user-bundle": "3.0.*@dev",

    "doctrine/orm": "2.*",
    "doctrine/doctrine-bundle": "1.3.*",
    "doctrine/doctrine-migrations-bundle": "2.1.*@dev",
    "doctrine/doctrine-fixtures-bundle": "2.2.*@dev",
    "stof/doctrine-extensions-bundle": "1.1.*@dev",
    "twig/extensions": "~1.2",

    "knplabs/gaufrette": "0.2.*@dev",
    "knplabs/knp-gaufrette-bundle": "0.2.*@dev",
    "knplabs/knp-paginator-bundle": "2.4.*@dev",

    "jms/security-extra-bundle": "1.6.1",
    "jms/serializer-bundle": "0.13.*@dev",

    "oneup/uploader-bundle": "0.9.*@dev",

    "egeloen/google-map": "1.4.*@dev",
    "egeloen/google-map-bundle": "2.2.*@dev",
    "marlon-be/marlon-ogone": "1.0.*@stable",

    "simplethings/form-extra-bundle": "^1.1",
    "neutron/recaptcha": "dev-master",
    "phpro/chili-xml-parser": "dev-master",
    "phpro/chili-soap": "dev-master",
    "activecampaign/api-php": "~1.0",
    "videlalvaro/php-amqplib": "~2.4",

    "sonata-project/datagrid-bundle": "2.2.*@dev",
    "sonata-project/doctrine-orm-admin-bundle": "3.1.4",
    "sonata-project/admin-bundle": "3.18.2",
    "sonata-project/page-bundle": "3.4.1",
    "sonata-project/notification-bundle": "3.1.0",
    "sonata-project/easy-extends-bundle": "~2.1",
    "sonata-project/translation-bundle": "dev-master",
    "sonata-project/formatter-bundle": "3.2.1",
    "sonata-project/media-bundle": "3.5.1",
    "sonata-project/intl-bundle": "2.2.0",
    "sonata-project/seo-bundle": "2.0@dev",
    "michelf/php-markdown": "1.4.0",
    "knplabs/knp-markdown-bundle": "^1.4",
    "sonata-project/classification-bundle": "3.0.0",

    "sylius/cart": "0.12.*",
    "sylius/resource": "0.12.*",
    "sylius/order": "0.12.*",
    "sylius/sequence": "0.12.*",
    "sylius/originator": "0.12.*",
    "sylius/registry": "0.12.*",
    "sylius/storage": "0.12.*",
    "sylius/cart-bundle": "0.12.*",
    "sylius/resource-bundle": "0.12.*",
    "sylius/sequence-bundle": "0.12.*",
    "sylius/money-bundle": "0.12.*",
    "sylius/order-bundle": "0.12.*",
    "sylius/promotion-bundle": "0.12.*",
    "sylius/flow-bundle": "0.12.*",
    "sylius/addressing-bundle": "0.12.*",
    "sylius/shipping-bundle": "0.12.*",
    "winzou/state-machine-bundle": "0.2.*",
    "sylius/payment-bundle": "0.12.*",
    "sylius/payum-bundle": "0.12.*",
    "sylius/currency-bundle": "0.12.*",
    "sylius/currency": "dev-bugfixes as 0.12.0.0",
    "sylius/pricing-bundle": "0.12.*",
    "sylius/taxation-bundle": "0.12.*",

    "payum/payum": "~0.12.0",
    "payum/payum-bundle": "~0.12.2",
    "friendsofsymfony/elastica-bundle": "~3.1",
    "setasign/fpdi": "^1.5",
    "setasign/fpdi_pdf-parser": "^1.1",
    "ddeboer/vatin-bundle": "^1.0",
    "ruflin/elastica": "dev-bugfix as 2.0.0",
    "setasign/fpdf": "^1.7",
    "symfony/var-dumper": "^3.1"
}