Bump github.com/stretchr/testify from 1.8.0 to 1.8.1 (#96)

Bumps [github.com/stretchr/testify](https://github.com/stretchr/testify) from 1.8.0 to 1.8.1.
- [Release notes](https://github.com/stretchr/testify/releases)
- [Commits](https://github.com/stretchr/testify/compare/v1.8.0...v1.8.1)

---
updated-dependencies:
- dependency-name: github.com/stretchr/testify
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/hashicorp/go-version v1.6.0
 	github.com/iancoleman/strcase v0.2.0
 	github.com/kr/pretty v0.1.0 // indirect
-	github.com/stretchr/testify v1.8.0
+	github.com/stretchr/testify v1.8.1
 	github.com/tj/assert v0.0.3
 	github.com/ulikunitz/xz v0.5.10
 	github.com/xor-gate/ar v0.0.0-20170530204233-5c72ae81e2b7