dep: update tm-db to 0.4.0 (#4289)

* dep: update tm-db to 0.4.0

- update 0.4.0 as it is a breaking change and cannot be handled by depndabot

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

*  more work towards error handling

* error and emtpy bytes handling

* work on tests

* add changelog entry, change some error handling

* address some pr comments

* panic in a few more places

* move error higher up

* redo some error handling

* fix some bz == nil to len(bz) == 0

* change statebytes

go.mod

@@ -19,7 +19,6 @@ require (
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/libp2p/go-buffer-pool v0.0.2
 	github.com/magiconair/properties v1.8.1
-	github.com/mitchellh/gox v1.0.1 // indirect
 	github.com/pkg/errors v0.9.0
 	github.com/prometheus/client_golang v0.9.3
 	github.com/rcrowley/go-metrics v0.0.0-20180503174638-e2704e165165
@@ -27,11 +26,9 @@ require (
 	github.com/snikch/goodman v0.0.0-20171125024755-10e37e294daa
 	github.com/spf13/cobra v0.0.1
 	github.com/spf13/viper v1.6.1
-	github.com/square/certstrap v1.2.0 // indirect
 	github.com/stretchr/testify v1.4.0
-	github.com/stumble/gorocksdb v0.0.3 // indirect
 	github.com/tendermint/go-amino v0.14.1
-	github.com/tendermint/tm-db v0.3.0
+	github.com/tendermint/tm-db v0.4.0
 	golang.org/x/crypto v0.0.0-20191206172530-e9b2fee46413
 	golang.org/x/net v0.0.0-20190628185345-da137c7871d7
 	golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a // indirect