Fix linter issues: vet

Makefile

@@ -124,6 +124,7 @@ gometalinter: require-gometalinter
 	    --enable=misspell \
 	    --enable=nakedret \
 	    --enable=unparam \
+	    --enable=vet \
 	    --exclude "^internal/.*\.pb\.go" \
 	    --exclude "^pql/pql.peg.go" \
 	    ./...

ctl/import.go

@@ -59,7 +59,7 @@ type ImportCommand struct { // nolint: maligned
 	Sort bool `json:"sort"`
 
 	// Reusable client.
-	client pilosa.InternalClient `json:"-"`
+	client pilosa.InternalClient
 
 	// Standard input/output
 	*pilosa.CmdIO

gossip/gossip.go

@@ -305,15 +305,15 @@ func newEventReceiver(logger *log.Logger, papi *pilosa.API) *eventReceiver {
 }
 
 func (g *eventReceiver) NotifyJoin(n *memberlist.Node) {
-	g.ch <- memberlist.NodeEvent{memberlist.NodeJoin, n}
+	g.ch <- memberlist.NodeEvent{Event: memberlist.NodeJoin, Node: n}
 }
 
 func (g *eventReceiver) NotifyLeave(n *memberlist.Node) {
-	g.ch <- memberlist.NodeEvent{memberlist.NodeLeave, n}
+	g.ch <- memberlist.NodeEvent{Event: memberlist.NodeLeave, Node: n}
 }
 
 func (g *eventReceiver) NotifyUpdate(n *memberlist.Node) {
-	g.ch <- memberlist.NodeEvent{memberlist.NodeUpdate, n}
+	g.ch <- memberlist.NodeEvent{Event: memberlist.NodeUpdate, Node: n}
 }
 
 func (g *eventReceiver) listen() {

http/error.go

@@ -16,9 +16,6 @@ package http
 
 // Error defines a standard application error.
 type Error struct {
-	// Machine-readable error code.
-	code string `json:"code,omitempty"`
-
 	// Human-readable message.
 	Message string `json:"message"`
 }

index.go

@@ -405,9 +405,8 @@ func (p indexSlice) Less(i, j int) bool { return p[i].Name() < p[j].Name() }
 
 // IndexInfo represents schema information for an index.
 type IndexInfo struct {
-	Name    string       `json:"name"`
-	options IndexOptions `json:"options"`
-	Fields  []*FieldInfo `json:"fields"`
+	Name   string       `json:"name"`
+	Fields []*FieldInfo `json:"fields"`
 }
 
 type indexInfoSlice []*IndexInfo

server/server_test.go

@@ -274,7 +274,6 @@ func TestMain_RecalculateHashes(t *testing.T) {
 	if err := client0.CreateField(context.Background(), "i", "f"); err != nil {
 		t.Fatal("create field:", err)
 	}
-	return
 
 	// Set some columns
 	data := []string{}