v0.8.1

What's Changed

• Create SECURITY.md by @iainmcgin in #213
• changelog: adopt changie fragment files to end CHANGELOG merge conflicts by @iainmcgin in #195
• client: restore Send on stream message() futures with concrete view types by @iainmcgin in #215
• ci: derive the MSRV check's toolchain from Cargo.toml by @iainmcgin in #217
• release: v0.8.1 by @iainmcgin in #216

Full Changelog: v0.8.0...v0.8.1