v1.6

A small release with a few features and fixes. Future development will utilise smaller, more regular releases to avoid long gaps waiting on feature X to be complete.

This release also changes the git branching model to use current for anything non-breaking, and the next branch now targets the next major version. This should avoid unncessary confusion for the wonderful contributors to pyinfra.

Operations:

• Make it possible to load relative (to CWD) templates (includes/bases/etc) (@themanifold)
• Add apt.dist_update operation (@bauen1)
• Fix files.Link fact & files.link operation where path pre-exists and is not a link

Connectors:

• Support setting shell_executable=None to pass raw commands to the target (@KuxaBeast)
• Fix handling of SSH proxy jump config
• Only load SSH host keys once
• Make it possible to specify a SSH config file via host.data.ssh_config_file