Add dispatchsrht-initdb
Use only necessary scopes for github tasks

Previously, dispatch.sr.ht required full access for the repo,
which raised questions in some projects and prevented them
to evaluate the service. This commit lowers permissions and now
service requires:

'write:repo_hook' - create a webhook
'repo:status' - commit statuses

It also adds the following scopes for the future:

'user:email' - send email
'repo_deployment' - deployment statuses
'read:org' - read-only access to organization's data
GitLab: fix check for existing repo ID
Tasks: use builds hostname in context
Upgrade to Alpine 3.11
Improve config.example.ini
Fix missing import from previous change
Use internal authorization for builds.sr.ht submit
Updates for single-sign-on support
Handle case where GitHub repo has been deleted
Update config.example.ini with GitLab details
Default gitlab integration to false
setup.py: add gitlab module
Fix up .builds/alpine.yml
Support running builds.sr.ht CI for GitLab commits
github/auth.py -> github/common.py
Generalize build submission
Add a build manifest for Debian packaging
Support forks with a different repository name

Prepend the source url with a $orig_dir:: to indicate to the
builds.sr.ht worker, how the repository directory should be called.
Update Arch Linux package signing key