Add MempoolClient to Client Interface (#3987)

* Add MempoolClient to Client Interface

closes #3984

- add mempoolclient interface to client interface

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

* Update CHANGELOG_PENDING.md

* add golang-ci version

rpc/client/interface.go

@@ -39,6 +39,7 @@ type Client interface {
 	SignClient
 	StatusClient
 	EvidenceClient
+	MempoolClient
 }
 
 // ABCIClient groups together the functionality that principally affects the

rpc/client/mock/client.go

@@ -37,6 +37,7 @@ type Client struct {
 	client.StatusClient
 	client.EventsClient
 	client.EvidenceClient
+	client.MempoolClient
 	cmn.Service
 }