Bump github.com/google/go-cmp from 0.5.9 to 0.6.0

Bumps [github.com/google/go-cmp](https://github.com/google/go-cmp) from 0.5.9 to 0.6.0.
- [Release notes](https://github.com/google/go-cmp/releases)
- [Commits](google/go-cmp@v0.5.9...v0.6.0)

---
updated-dependencies:
- dependency-name: github.com/google/go-cmp
  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/aligator/go.clipper v0.0.0-20200424185851-fc8a51077d44
 	github.com/ctessum/geom v0.2.10 // indirect
 	github.com/furstenheim/go-convex-hull-2d v0.0.0-20181121204724-08788ab09726
-	github.com/google/go-cmp v0.5.9
+	github.com/google/go-cmp v0.6.0
 	github.com/hschendel/stl v1.0.4
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.6.1 // indirect

go.sum

@@ -21,8 +21,8 @@ github.com/gonum/floats v0.0.0-20181209220543-c233463c7e82 h1:EvokxLQsaaQjcWVWSV
 github.com/gonum/floats v0.0.0-20181209220543-c233463c7e82/go.mod h1:PxC8OnwL11+aosOB5+iEPoV3picfs8tUpkVd0pDo+Kg=
 github.com/gonum/internal v0.0.0-20181124074243-f884aa714029 h1:8jtTdc+Nfj9AR+0soOeia9UZSvYBvETVHZrugUowJ7M=
 github.com/gonum/internal v0.0.0-20181124074243-f884aa714029/go.mod h1:Pu4dmpkhSyOzRwuXkOgAvijx4o+4YMUJJo9OvPYMkks=
-github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
-github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/hschendel/stl v1.0.4 h1:DXT5rkiXMUkbKw4Ndi1OYZ/a5SLR35TzxGj46p5Qyf8=
 github.com/hschendel/stl v1.0.4/go.mod h1:XQFFLKrq9YTaBpmouDui4JSaxMyAYkpD7elGSSj/y3M=
 github.com/jonas-p/go-shp v0.1.2-0.20190401125246-9fd306ae10a6/go.mod h1:MRIhyxDQ6VVp0oYeD7yPGr5RSTNScUFKCDsI5DR7PtI=