Add support for FOSSA

[danielmitterdorfer]

With this commit we add support in Rally to run license checks on third-party
dependencies with a separate tool called fossa. Note that this work is only a
preparation on the Rally side. This is intended to be run in CI and needs to be
supplemented by a corresponding CI job.

[hub-cap]

I am going to spin up a test machine to ensure this works properly

@elasticmachine run tests

[hub-cap]

This looks good. It complained about an environment variable but I dont think that needs to be solved in this PR.

My only question is ive seen some projects make the project field the entire github URL, whereas some do not. I dont know enought about fossa to know what is correct, and I assume you do :)

[hub-cap]

Not sure how I could have altered the tests by being on the machine but Im going to rerun them just in case on a pristine machine that I do not get on.

@elasticmachine run tests

[danielmitterdorfer]

Thanks for the review!

This looks good. It complained about an environment variable but I dont think that needs to be solved in this PR.

I checked the logs from the CI run as well and I think this is because I've created this PR before #1105 has been merged to master. I've merged master now and retriggered a CI run.

My only question is ive seen some projects make the project field the entire github URL, whereas some do not. I dont know enought about fossa to know what is correct, and I assume you do :)

The Github URL is autopopulated when you create a fossa configuration on the command line (with fossa init) and this property is used in the fossa UI to identify the project (see also their docs). I've explicitly changed this so it shows the nicer name "Rally" instead of the somewhat clunky URL. I hope that answers your question.