update deps, go mod tidy

go.mod

@@ -5,8 +5,8 @@ require (
 	github.com/gogo/protobuf v1.3.1
 	github.com/ipfs/go-log v1.0.4
 	github.com/libp2p/go-libp2p-blankhost v0.1.6
+	github.com/libp2p/go-libp2p-connmgr v0.2.3
 	github.com/libp2p/go-libp2p-core v0.5.6
-	github.com/libp2p/go-libp2p-connmgr v0.2.2-0.20200508190152-8ff0dd307f71
 	github.com/libp2p/go-libp2p-discovery v0.4.0
 	github.com/libp2p/go-libp2p-swarm v0.2.4
 	github.com/multiformats/go-multiaddr v0.2.2