Merge pull request #4955 from mitake/e2e-test

e2e: import fmt in etcdctlv3_test.go

e2e/etcdctlv3_test.go

@@ -15,6 +15,7 @@
 package e2e
 
 import (
+	"fmt"
 	"os"
 	"strconv"
 	"strings"