full-featured integration tests with Knot Resolver & Knot DNS

apkg is reaching feature parity with current Knot packaging setup.

As a final task for %v0.1 , A CI pipeline must be created that will ensure apkg continues to work for Knot packaging.

The pipeline must ensure following on all supported platforms:

• apkg build successfully creates dev packages from Knot Resolver & DNS repos
• apkg build --upstream successfully creates upstream package from latest upstream Knot Resolver & DNS archives

For now apkg branches in Knot Resolver & DNS will be used and later switched to master.