Symfony server stub

I'm a beginner concerning building a web service and I documented my API using Swagger and then exported it to a php-symfony server stub project. Now I'm really having a lot of issues with setting up the project since everything is so different in the newer versions. I can't really follow the readme.md at all and I cant find any information anywhere to be honest concerning this.

When inputting the path of it doesn't install it tells me that Your requirements could not be resolved to an installable set of packages. Does this mean its incompatible with the latest Version of Symfony? How do I set up the repository path ? 

How do I enable it in the Kernel since my kernel.php doesnt look like the one they based it on ?

Please I am super frustrated and can't really figure it out myself so It would be great to get some help with this very basic issue.

Installation request for swagger/server-bundle dev-master -> satisfiable by swagger/server-bundle[dev-master].
- swagger/server-bundle dev-master requires symfony/framework-bundle ^2.3|^3.0 -> no matching package found.

How do I solve this ? I can't seem to find a compatible symfony version.