Upgrade to tm version 23.0. (#1927)

* Start upgrade. Currently go test ./... hangs.

* (squash this) Fix staking tests

* wip

* note what changes need to be made to make this work on tm v0.23.0

* Fix addr -> pubkey map

* cleanup code

* Fix slashing test failures except for begin blocker

* fix all slashing tests

* fix lcd tests

* Address PR comments

* add link to changelog.

* (wip) start making addrToPubkey map persisted. Since amino can't handle maps,
we have to change from what this commit is doing.

* Use the correct method of storing a map

* (squash this) address PR comments

* Did you run 'make'?

* remove gaiadebug binary

client/tx/sign.go

@@ -44,5 +44,5 @@ func SignTxRequstHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write(sig.Bytes())
+	w.Write(sig)
 }