builder/digitalocean: fix unit tests

builder/digitalocean/builder_test.go

 package digitalocean
 
 import (
-	"github.com/mitchellh/packer/packer"
-	"os"
 	"strconv"
 	"testing"
-)
 
-func init() {
-	// Clear out the credential env vars
-	os.Setenv("DIGITALOCEAN_API_KEY", "")
-	os.Setenv("DIGITALOCEAN_CLIENT_ID", "")
-}
+	"github.com/mitchellh/packer/packer"
+)
 
 func testConfig() map[string]interface{} {
 	return map[string]interface{}{
-		"client_id": "foo",
-		"api_key":   "bar",
+		"api_token": "bar",
 	}
 }
 
@@ -78,7 +71,6 @@ func TestBuilderPrepare_Region(t *testing.T) {
 	expected := "sfo1"
 
 	// Test set
-	config["region_id"] = 0
 	config["region"] = expected
 	b = Builder{}
 	warnings, err = b.Prepare(config)
@@ -114,7 +106,6 @@ func TestBuilderPrepare_Size(t *testing.T) {
 	expected := "1024mb"
 
 	// Test set
-	config["size_id"] = 0
 	config["size"] = expected
 	b = Builder{}
 	warnings, err = b.Prepare(config)
@@ -150,7 +141,6 @@ func TestBuilderPrepare_Image(t *testing.T) {
 	expected := "ubuntu-14-04-x64"
 
 	// Test set
-	config["image_id"] = 0
 	config["image"] = expected
 	b = Builder{}
 	warnings, err = b.Prepare(config)