RUSTSEC-2020-0056: stdweb is unmaintained

[github-actions[bot]]

stdweb is unmaintained

Details
Status	unmaintained
Package	stdweb
Version	0.4.20
URL	https://github.com/koute/stdweb/issues/403
Date	2020-05-04

The author of the stdweb crate is unresponsive.

Maintained alternatives:

• wasm-bindgen
• js-sys
• web-sys

See advisory page for additional details.