test suite with continuous integration

[1ma]

Addresses #24

This PR introduces isolation tests written in Go and integration tests written in Python, using the pyln-testingframework. A pipeline has been added to run the tests on each push to Github.

The tests themselves are not exhaustive, this PR is meant to be the foundation for further work.

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The test suite has uncovered a couple bugs that are fixed in this same PR.

1. bcli defines more options than trustedcoin, and in particular the pyln-testing framework assumes bitcoin-datadir exists, though trustedcoin did not have it. It has been added with a warning that it is not used, otherwise pyln-testing cannot run.

2. estimatefees returns bad estimates on regtest, and an early return has been added with fake fee estimations. This is consistent with what bcli does.

[fiatjaf]

Great, now we have Python in this codebase.

[fiatjaf]

Thank you, sir, you are a hero.

[ca-ruz]

@1ma I ran the integration test locally and it's not actually disabling bcli (so trustedcoin is not running). Curious if you're planning on fleshing this out?

[1ma]

Duh, you're right. opts={...} should be options={...}. I used to call get_nodes() instead of get_node(), in that function the argument is called opts.

Can you confirm this also fixes the problem for you before I submit a PR?

[ca-ruz]

Ahh I see. I already tried it with options={...} and it's still failing. I'm having a similar issue with Sauron. You can take a look at this, it should help out: lightningd/plugins#584 (comment)