ntfy-alertmanager v0.2.0

New features:

- alert-mode: Alerts which are grouped together can now be split apart.
  Those alerts will be cached to avoid repetitions.
- silence: A silence action can be added to the ntfy messages. This uses
  the (proxied) Alertmanger API to silence alerts by their labels.
- resolved: Add tags for resolved alerts

Thorben Günther (26):
      readme: Add CI status badge
      Add Dockerfile and publish image
      Move notification creation into new function
      Publish a dev docker image
      CI: Add missing secret for publishing docker images
      config: Load all label settings
      config: Add parsing test
      Add version flag
      config: Add alert-mode
      Support sending grouped alerts on their own
      single mode: Cache alert fingerprints
      cache: Add config options for duration and cleanup interval
      Log incoming, parsed alert
      cache: Take alert status (firing, resolved) into account
      config: Add required settings for silencing alerts
      Add ability to silence alerts with ntfy action
      alertmanager: Support basic auth
      silence: Add to multi alert-mode as well
      silence: Don't add silence action to resolved alerts
      Refactor structs to use map[string]string
      alertmanger: Add setting to overwrite URL
      silence: Parse Alertmanager API response
      silence: Fix broken ntfy action
      Upgrade dependencies
      cache: Only cache the alert if it was published successfully
      Add tags for resolved alerts