v9.0.0

This new version of mxpy(v9) contains quite a few changes over the previous one.
Some of the commands that suffered changes are: mxpy deps, mxpy contract and mxpy wallet.

Please make sure that you read the migration guide.

The release has been prepared here.

What's Changed

• Cargo install wasm-opt and twiggy when installing rust by @popenta in #340
• Install rust globally by @popenta in #331
• Contract templates and contract new from template using sc-meta by @popenta in #342
• Message signing and verifying by @popenta in #343
• Remove tag argument from mxpy deps by @popenta in #344
• Fix type of pem index argument by @popenta in #346
• Smart contract projects cleanup by @popenta in #348
• Use latest wallet package by @popenta in #354
• Fix unit tests by @popenta in #357
• Integrate latest packages by @popenta in #359

Full Changelog: v8.1.6...v9.0.0