* Update Go to 1.18
* Update circleci machine image.
* Switch maildev to new upstream image location.
* Update Go modules to 1.17 format.
* Make dependabot monthly to match prometheus/prometheus.
Signed-off-by: SuperQ <superq@gmail.com>
Add dependabot dependency check in order to maintain dependencies up-to-date and security updates on time.
Signed-off-by: David Ureba <david.ureba@aiven.io>