0.3.0 -- Bug Fixes, Small API Improvements

Improvements

• assorted DX and infrastructure improvements (#116, #123, #127, #128, #135, #138, #145, #146)
• convert some as casts to proper conversion (#117, #118, #120, #121)
• make Client::{controller,partition}_client sync (#136)

Dependency Updates

• rustls-pemfile to 1.0 (#126)
• uuid to 1.0 (#131)

Bug Fixes

• multiple cancellation and panic safety fixes (#113, #115)
• Java interopt, esp. for Snappy-compressed messages (#108)
• fix potential OOM cases (#138, #141)
• remove potentially buggy Redpanda quirk (#150)
• documentation (#151)