Set up automated builds on travis/circleci/you_name_it

[ffissore]

It would be beneficial to have automated builds for all platforms for all pushes to master

• it would give a sense of confidence (it builds!), especially as tests are added
• it would allow occasional users to give a try to the latest changes, especially when testing something on multiple platforms

[ffissore]

I'm posting this issue here rather than on upstream because I think we need it now. Think when this fork will be ready to be merged and we will need feedback from users: we can get more feedback if we don't ask folks to build software

[cdberkstresser]

Working on a github workflow to do this.

[cdberkstresser]

I've added a workflow for building the deb file on the github Ubuntu 18.04 image. I haven't yet figured out how to extract the file back from the image into the releases folder, but that's where it's it.

[braiam]

@cdberkstresser you need to use the v2-preview of upload-artifact, as it has support for wildcards actions/upload-artifact#62