Go(deps): bump github.com/go-openapi/errors from 0.20.4 to 0.21.0

Bumps [github.com/go-openapi/errors](https://github.com/go-openapi/errors) from 0.20.4 to 0.21.0.
- [Commits](go-openapi/errors@v0.20.4...v0.21.0)

---
updated-dependencies:
- dependency-name: github.com/go-openapi/errors
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/TykTechnologies/goverify v0.0.0-20160822133757-7ccc57452ade
 	github.com/TykTechnologies/serverless v0.0.0-20180728220237-1d6be198f145
 	github.com/TykTechnologies/tyk v2.9.3+incompatible
-	github.com/go-openapi/errors v0.20.4
+	github.com/go-openapi/errors v0.21.0
 	github.com/go-openapi/runtime v0.26.0
 	github.com/go-openapi/strfmt v0.21.7
 	github.com/go-openapi/swag v0.22.4

go.sum

@@ -176,8 +176,8 @@ github.com/go-openapi/analysis v0.21.4/go.mod h1:4zQ35W4neeZTqh3ol0rv/O8JBbka9Qy
 github.com/go-openapi/errors v0.19.8/go.mod h1:cM//ZKUKyO06HSwqAelJ5NsEMMcpa6VpXe8DOa1Mi1M=
 github.com/go-openapi/errors v0.19.9/go.mod h1:cM//ZKUKyO06HSwqAelJ5NsEMMcpa6VpXe8DOa1Mi1M=
 github.com/go-openapi/errors v0.20.2/go.mod h1:cM//ZKUKyO06HSwqAelJ5NsEMMcpa6VpXe8DOa1Mi1M=
-github.com/go-openapi/errors v0.20.4 h1:unTcVm6PispJsMECE3zWgvG4xTiKda1LIR5rCRWLG6M=
-github.com/go-openapi/errors v0.20.4/go.mod h1:Z3FlZ4I8jEGxjUK+bugx3on2mIAk4txuAOhlsB1FSgk=
+github.com/go-openapi/errors v0.21.0 h1:FhChC/duCnfoLj1gZ0BgaBmzhJC2SL/sJr8a2vAobSY=
+github.com/go-openapi/errors v0.21.0/go.mod h1:jxNTMUxRCKj65yb/okJGEtahVd7uvWnuWfj53bse4ho=
 github.com/go-openapi/jsonpointer v0.19.3/go.mod h1:Pl9vOtqEWErmShwVjC8pYs9cog34VGT37dQOVbmoatg=
 github.com/go-openapi/jsonpointer v0.19.5 h1:gZr+CIYByUqjcgeLXnQu2gHYQC9o73G2XUeOFYEICuY=
 github.com/go-openapi/jsonpointer v0.19.5/go.mod h1:Pl9vOtqEWErmShwVjC8pYs9cog34VGT37dQOVbmoatg=