Limit number of concurrent requests to builds/register.json

See merge request !518

Kubernetes private credentials

Closes gitlab-ce#27763

See merge request !520

Make it easier to run tests locally

See merge request !506

Automatically create image pull secrets for accessing GitLab Container Registry and pass it to Kubernetes

Switch from CI API v1 to API v4

Closes #2141

See merge request !517

improve details around limits

See merge request !502

Rename the binary on download to use gitlab-runner as command

See merge request !510

Fix word consistency in autoscaling docs

See merge request !519

   + auto-scaling => autoscaling

This change is required to keep consistency for search and other documentation  https://docs.gitlab.com/runner/configuration/autoscale.html