JupyterLab+Colab extension

[DanielSchiavini]

Fixes #83

• Fix pre-commit checks
• Create a jupyter server extension
• Inject ethers and boa code via Python Javascript
• Implement front-end callbacks via JS file
• Simplify the browser signer
• Usage example available in Launch beta.vyperlang.org try.vyperlang.org#1
• Add support for Google Colab
• Figure out how to implement tests with jupyter dependencies

Usage

import boa
from boa.integrations.jupyter import BrowserSigner
from boa.network import NetworkEnv

boa.set_env(NetworkEnv(...))
boa.env.add_account(BrowserSigner())

Cute animal in Jupiter

source

[DanielSchiavini]

This PR was drafted because we wanted to investigate support for notebook v6.

Since v6 is deprecated and works quite differently, I discussed with @charles-cooper that it was best to support JupyterLab and Google Colab only.

[charles-cooper]

dark magic :)

[charles-cooper]

incredible work. thank you!!!

[charles-cooper]

it would be cool to get the RPC url from the browser signer (h/t @bout3fiddy for the idea), but out of scope here. will open a new issue for it