poetry dependency management

[v-goncharenko]

I moved package management to poetry as I suggested in #146

Separated development dependencies from direct ones. Run tests, evaluated run.py and built docs (here got some errors not related to dependencies).

I've investigated requirements.txt and found funny things:

• pillow and patool are not used anywhere, so I skipped adding them to poetry setup
• pyunpack used only once and could be easily be replaced with standard library call (I'll open an issue later, or fix it directly with PR)
• m2r is no longer supported, so I changed it to m2r2 which is a supported fork
• numpy, scipy and Sphinx are explicitly used but was not placed to explicit dependencies, fixed it

Last but not least, I'll describe poetry (as well as development env) setup procedure in CONTRIBUTING file in another PR. (this requires #151 to be merged to avoid conflicts)

[v-goncharenko]

Another thing I've noticed - need to update Actions pipelines (switch them to poetry too). I'll do that a bit later

[v-goncharenko]

Finished!

We are completely ready to move to stable explicit crossplatform dependencies =)

[sylvchev]

Thank you ! This PR is really nice.

Regarding some specific dependencies :

I've investigated requirements.txt and found funny things:

* `pillow` and `patool` are not used anywhere, so I skipped adding them to poetry setup

* `pyunpack` used only once and could be easily be replaced with standard library call (I'll open an issue later, or fix it directly with PR)

pyunpack is used to unpack archive files for Wang2016 dataset. It is a frontend that need some backend packages to work correctly, and patool is the "backend" package used to unpack the required archive. If you could replace it with a standard library call, this could help to reduce the dependency to other package. For now, I think you need reintegrate patool in the requirements.

Last but not least, I'll describe poetry (as well as development env) setup procedure in CONTRIBUTING file in another PR. (this requires #151 to be merged to avoid conflicts)

This is a good idea to update the contributing page.

[v-goncharenko]

Done

[v-goncharenko]

@sylvchev I've added setup instructions to contribution file. (and also fixed the issues you pointed in change request)

I guess this makes this PR mergeable.

[sylvchev]

Just two typos to fix and we could merge!

[v-goncharenko]

Great!

Then navigate straight to PyPI!
I'll checkout what is needed for that and let's discuss it during office hours.