Commit e3ed3ba7c9 bumps golang/mock to 1.6.0 in hack/tools.
It makes sense to keep its version in sync, so let's do the same
in the top level go.mod.
Generated by
./hack/pin-dependency.sh github.com/golang/mock v1.6.0
./hack/lint-dependencies.sh
./hack/update-vendor.sh
./hack/update-internal-modules.sh
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
fd21ade6d5