Add MIT License

[Zac-HD]

Adding a permissive licence to the tracer allows it to be incorporated into other tools.

I'll open a PR soon on https://github.com/gleb-sevruk/pycrunch-tracing-webui with a non-open-source license; per our call - the idea is that the commercialisable part is the UI to interact with traces, rather than the trace collection.

[gleb-sevruk]

Maybe this license can work: https://github.com/gleb-sevruk/pycrunch-engine/blob/master/LICENCE.txt

Free for open source, but restrictive for commercial

[Zac-HD]

It's surprisingly difficult to write a license that works all over the world. For example:

• If you don't have a company named "PyCrunch", that license may not have any legal meaning
• Open-source projects can also be "commerical use" - consider e.g. Pytorch (both OSS and a commercial project by Facebook)
• The part about asking permission is unclear; by default anyone would need permission - so some courts might interpret it as meaning "so long as you asked, the answer doesn't matter"!

Overall, the choice is basically between a standard OSS license, or writing a custom commercial license. From our conversation the other day, I'd noted down that the trace-collector (this repo) could be MIT-licensed. Then the web UI, which is much more valuable as a service (even before collaboration features etc) could use a non-OSS paid license, with a free-for-personal-noncommercial-use clause.

[Zac-HD]

The idea is that https://github.com/gleb-sevruk/pycrunch-tracing-webui/pull/2 is the commercially valuable part; while the trace collector is given away for free to get more customers for the trace viewer.

(which is the exact tactic I'm trying: Hypothesis is free and open source, and hopefully that creates customers for HypoFuzz)