v0.2.1 bump

[rvagg]

No description provided.

[rvagg]

## incompatible changes
Config: old is comparable, new is not

bah!

tenuous reason but I'll go with it cause numbers are cheap

[github-actions]

Suggested version: v0.3.0

Comparing to: v0.2.0 (diff)

Changes in go.mod file(s):

(empty)

gorelease says:

# github.com/ipld/go-trustless-utils/testutil
## compatible changes
AsIdentity: added
CorrectedMemStore: added
MakeDagWithIdentity: added
ParentStore: added
ZeroReader: added

# github.com/ipld/go-trustless-utils/traversal
## incompatible changes
Config: old is comparable, new is not
## compatible changes
Config.OnBlockIn: added

# diagnostics
go.sum: one or more sums are missing. Run 'go mod tidy' to add missing sums.

# summary
Suggested version: v0.3.0

gocompat says:

Your branch is up to date with 'origin/master'.

Automatically created GitHub Release

A draft GitHub Release has been created.
It is going to be published when this PR is merged.
You can modify its' body to include any release notes you wish to include with the release.