ci: fix go vet and add Go 1.11.x

.travis.yml

@@ -4,6 +4,7 @@ go:
   - 1.8.x
   - 1.9.x
   - 1.10.x
+  - 1.11.x
   - master
 
 before_install:

routes/repo/branch.go

@@ -124,7 +124,7 @@ func DeleteBranchPost(c *context.Context) {
 	if len(commitID) > 0 {
 		branchCommitID, err := c.Repo.GitRepo.GetBranchCommitID(branchName)
 		if err != nil {
-			log.Error(2, "Failed to get commit ID of branch %q: %v", err)
+			log.Error(2, "Failed to get commit ID of branch %q: %v", branchName, err)
 			return
 		}