Merge pull request #30 from extism/release-0.3.4

release: 0.3.4

chore: use updated version of extism-pdk-derive, bump pdk version (#28)

chore: bump extism-pdk to 0.3.2 (#25)

fix: let fail if derive publish already exists

chore: update dependencies, run clippy, bump version to 0.3 (#20)

* chore: update depdencies

* chore: clippy

release: Bump derive as well

chore: bump versions for v0.1.1 release (#13)

Merge pull request #4 from extism/improve-api

Add `function` and `encoding` macros + simplify host interface