TST: Finish moving to Azure CI

[pllim]

Fix #181

Follow up of #190

TODO:

• Fix codecov upload. Missing token? Try it Joe's way: https://github.com/astroconda/delivery_merge/blob/master/azure-pipelines.yml NOPE Asked at Unable to read token off Azure pipeline secret variable codecov/codecov-python#203 -- So turns out PR from fork cannot see the token. It will only run when merged. Will try to see if I can enable it separately on my fork. NOPE Enabled it on my fork, but my PR still cannot upload report. So it will only be calculated on merge regardless. 🤔 Also see WIP: Azure pipelines configuration astropy/astropy#8445 (comment) Can we live with PR not having coverage available before merge??? Check this after merge
• Move common stuff into a template.
• Do we need stages?
• Set up a cron job. Need a dedicated YML file for this. Can reuse code from template. Set this up in Azure account after merge
• Can we allow astropy dev job to fail? NOPE, NOT SUPPORTED YET.
• Can we upload doc artifacts like CircleCI yet? Maybe with https://docs.microsoft.com/en-us/azure/storage/blobs/storage-blob-static-website ? NOPE, NOT FREE. https://azure.microsoft.com/en-us/pricing/details/storage/blobs/
• Inspect test log carefully before merge.
• Update README badges.