Merge pull request keel-hq#264 from keel-hq/feature/helm_match_tag

adding helm match tag

Merge pull request keel-hq#257 from keel-hq/feature/cron_jobs

keel-hq#251 initial work on cron job support

Merge pull request keel-hq#258 from keel-hq/feature/approvals_in_mem

Feature/approvals in mem

Merge pull request keel-hq#231 from keel-hq/feature/optional_link

Feature/optional link

Merge pull request keel-hq#229 from keel-hq/feature/approvals_reset_o…

…n_digest_change

Feature/approvals reset on digest change

Merge pull request keel-hq#228 from keel-hq/feature/registry_cfg

Feature/registry cfg

Merge pull request keel-hq#221 from azr/ft/fix-match-tag

fix match tag during versionned update

Merge pull request keel-hq#219 from keel-hq/feature/deregister_tracke…

…d_images

unwatching images that are not tracked anymore

Merge pull request keel-hq#208 from keel-hq/feature/tests

Feature/tests

Merge pull request keel-hq#204 from keel-hq/bugfix/cache_copy

Bugfix/cache copy