Bump github.com/google/go-cmp from 0.5.2 to 0.5.6

Bumps [github.com/google/go-cmp](https://github.com/google/go-cmp) from 0.5.2 to 0.5.6.
- [Release notes](https://github.com/google/go-cmp/releases)
- [Commits](google/go-cmp@v0.5.2...v0.5.6)

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

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/golang/mock v1.4.4
 	github.com/golang/protobuf v1.4.2
 	github.com/google/certificate-transparency-go v1.1.0 // indirect
-	github.com/google/go-cmp v0.5.2
+	github.com/google/go-cmp v0.5.6
 	github.com/google/tink/go v1.4.0-rc2
 	github.com/google/trillian v1.3.10
 	github.com/grpc-ecosystem/go-grpc-middleware v1.2.0

go.sum

@@ -297,6 +297,7 @@ github.com/google/go-cmp v0.5.0 h1:/QaMHBdZ26BB3SSst0Iwl10Epc+xhTquomWX0oZEB6w=
 github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.2 h1:X2ev0eStA3AbceY54o37/0PQ/UWqKEiiO2dKL5OPaFM=
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-replayers/grpcreplay v0.1.0/go.mod h1:8Ig2Idjpr6gifRd6pNVggX6TC1Zw6Jx74AKp7QNH2QE=
 github.com/google/go-replayers/httpreplay v0.1.0/go.mod h1:YKZViNhiGgqdBlUbI2MwGpq4pXxNmhJLPHQ7cv2b5no=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=