v0.4.2

What's Changed

• Update envelopers to 0.5.0 by @bennetthardwick in #5
• Update envelopers to 0.5.1, enable tokio by @bennetthardwick in #6

Full Changelog: v0.4.1...v0.4.2

Fix runtime dependency issue for source gem

To build the source gem, you need rb_sys. However, you don't need it to run the gem.
Absent an add_build_dependency method on Gem::Specification, a conditional seems the best approach available.

Promote the Simple key provider to general-purpose use

With some improvements in the underlying envelopers cryptography, the Simple key provider is now secure for general-purpose use.
Go forth and envelop!

Use the published version of the 'envelopers' crate

Now that it's released and available on crates.io, we should definitely use that instead of a git reference.

Automated gem builds

No more needing Rust installed!

Add build flags to 'source' builds

The macOS local builds need the no-link support flags as well.

Tweak build command

There's always one thing you miss...

A new build system

Now we should be able to produce native gems for multiple platforms that
stand a small chance of working.

Tweak build process for M1 macs

Darwin's just gotta be different, doesn't it?

Fix a glitch in the Cargo.toml

v0.1.1

Fix a glitch in the Cargo.toml