Interactive Python SDK Sandbox

[cshepherd]

Combine Jerzy's updated Python SDK with interactive web REPL "Skulpt" (MIT licensed) to create a sandbox to showcase the Python SDK, much as the current sandbox showcases the Javascript SDK with an interactive web REPL.

[cshepherd]

Pyodide is the technology that I've selected for this. It works by compiling CPython to WebAssembly. Transpiler (Python-to-JS) approaches such as Brython, Transcrypt, and Skulpt/Trinket download somewhat faster, but they do not support packages. That narrows the choice to Pyodide and PyPy.

The approach I'll be taking with Pyodide, is creating a package similar to the existing @cryptosat/jsconsole component, except that it will be a Python interpreter instead of JS. The UI will be tabbed (JS and Python tabs) and permit freely switching back and forth between the languages. I have seen this approach with other SDK demo pages that support multiple languages, and it has been a pleasant experience.

The Python SDK is now ready to use, so I have no blockers.

[cshepherd]

See http://github.com/cryptosat/cryptosim-tutorial/pull/40 for design review and code review.