Unify distro_signatures.json

[tiltingpenguin]

Currently we have 3 instances for distro_signatures.json:

1 in libcobblersignatures,
1 in cobbler and
1 in cobbler.github.io

We want to unify these and thus reduce the effort for maintaining an example signatures file. The idea is to have a static site in cobbler.github.io that serves the examples for all the different schema versions

[SchoolGuy]

I want to extend on this a littlebit more:

• This repository will use GitHub pages to upload all versions of the schema that are available.
• The server repository version of distro_signatures.json will be deleted once Integrate this project into the main server #44 is done.
• The versions on cobbler.github.io will stay unmaintained there for archival purposes.
• The server will use the new schema-based versioning as an URL for updating the distro_signatures.json file.
• The new URL should then subsequently look roughly like the following:
  • https://cobbler.github.io/libcobblersignatures/v1/data.json
  • https://cobbler.github.io/libcobblersignatures/v1/schema.json
• Thus in the repository will at all times live all schemas with all distro_signatures.json files in the main branch.
• The new repository structure could look like the following:

...
distro_signatures/
    v1/
        data.json
        schema.json
...

[SchoolGuy]

This issue is dependent on #63