Update dependency on Trillian (#919)

This change updates to the latest pre-release version. We will update
to stable after Trillian is released.

go.mod

@@ -4,39 +4,28 @@ go 1.16
 
 require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
-	github.com/form3tech-oss/jwt-go v3.2.5+incompatible // indirect
 	github.com/fullstorydev/grpcurl v1.8.6
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/mock v1.6.0
 	github.com/golang/protobuf v1.5.2
 	github.com/google/go-cmp v0.5.8
-	github.com/google/trillian v1.4.0
+	github.com/google/trillian v1.4.1-0.20220503161811-32257c5c3ca0
 	github.com/gorilla/mux v1.8.0
-	github.com/jonboulle/clockwork v0.3.0 // indirect
 	github.com/kylelemons/godebug v1.1.0
-	github.com/mattn/go-runewidth v0.0.13 // indirect
 	github.com/mattn/go-sqlite3 v1.14.10
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826
 	github.com/prometheus/client_golang v1.12.1
-	github.com/prometheus/common v0.34.0 // indirect
 	github.com/rs/cors v1.8.2
 	github.com/sergi/go-diff v1.2.0
 	github.com/spf13/cobra v1.4.0
 	github.com/spf13/pflag v1.0.5
-	github.com/stretchr/testify v1.7.1 // indirect
 	github.com/tomasen/realip v0.0.0-20180522021738-f0c99a92ddce
 	github.com/transparency-dev/merkle v0.0.0-20220427153749-09877c5f5967
-	github.com/urfave/cli v1.22.7 // indirect
 	go.etcd.io/etcd/client/v3 v3.5.4
 	go.etcd.io/etcd/etcdctl/v3 v3.5.4
 	go.etcd.io/etcd/v3 v3.5.4
-	go.opentelemetry.io/contrib v1.6.0 // indirect
-	go.uber.org/atomic v1.9.0 // indirect
-	go.uber.org/multierr v1.8.0 // indirect
-	go.uber.org/zap v1.21.0 // indirect
 	golang.org/x/crypto v0.0.0-20220411220226-7b82a4e95df4
 	golang.org/x/net v0.0.0-20220425223048-2871e0cb64e4
-	golang.org/x/sys v0.0.0-20220422013727-9388b58f7150 // indirect
 	golang.org/x/time v0.0.0-20220411224347-583f2d630306
 	google.golang.org/genproto v0.0.0-20220426171045-31bebdecfb46 // indirect
 	google.golang.org/grpc v1.46.0