remove image name check in tencentcloud builder

Spinnaker uses packer to create images, but tencentcloud builder
has name check to forbidden special characters such as dot(.) while
it is absolutely valid in API side.

This patch simply removes this limitation.

builder/tencentcloud/cvm/image_config.go

@@ -2,7 +2,6 @@ package cvm
 
 import (
 	"fmt"
-	"regexp"
 
 	"github.com/hashicorp/packer/template/interpolate"
 )
@@ -26,11 +25,6 @@ func (cf *TencentCloudImageConfig) Prepare(ctx *interpolate.Context) []error {
 		errs = append(errs, fmt.Errorf("image_name must be set"))
 	} else if len(cf.ImageName) > 20 {
 		errs = append(errs, fmt.Errorf("image_num length should not exceed 20 characters"))
-	} else {
-		regex := regexp.MustCompile("^[0-9a-zA-Z\\-]+$")
-		if !regex.MatchString(cf.ImageName) {
-			errs = append(errs, fmt.Errorf("image_name can only be composed of letters, numbers and minus sign"))
-		}
 	}
 
 	if len(cf.ImageDescription) > 60 {

builder/tencentcloud/cvm/image_config_test.go

@@ -11,9 +11,9 @@ func TestTencentCloudImageConfig_Prepare(t *testing.T) {
 		t.Fatalf("shouldn't have err: %v", err)
 	}
 
-	cf.ImageName = "foo:"
-	if err := cf.Prepare(nil); err == nil {
-		t.Fatal("should have error")
+	cf.ImageName = "foo.:"
+	if err := cf.Prepare(nil); err != nil {
+		t.Fatal("shouldn't have error")
 	}
 
 	cf.ImageName = "foo"