Consider using Azure for CI

[ndmitchell]

https://azure.microsoft.com/en-us/blog/announcing-azure-pipelines-with-unlimited-ci-cd-minutes-for-open-source/ - a six hour limit on fast VMs for free could be very useful

[snowleopard]

@ndmitchell Wow, sounds too goo to be true, but we should definitely give it a try!