io/key: delete Event.String

The String method doesn't add anything in addition to the default Go
formatting of the type.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

io/key/key.go

@@ -11,7 +11,6 @@ package key
 
 import (
 	"encoding/binary"
-	"fmt"
 	"math"
 	"strings"
 
@@ -367,10 +366,6 @@ func (FocusEvent) ImplementsEvent()     {}
 func (SnippetEvent) ImplementsEvent()   {}
 func (SelectionEvent) ImplementsEvent() {}
 
-func (e Event) String() string {
-	return fmt.Sprintf("%v %v %v}", e.Name, e.Modifiers, e.State)
-}
-
 func (m Modifiers) String() string {
 	var strs []string
 	if m.Contain(ModCtrl) {