datasource/http: change Outputs->ExpectedOutputs

The acceptance tests for the HTTP datasource had a `Outputs` attribute
for checking the output of the command for a specific regexp pattern.
As pointed out, given the expectative nature of the attribute, naming it
`Outputs` did not make the intent clear, so we rename it to
`ExpectedOutputs` with this commit.

datasource/http/data_acc_test.go

@@ -29,16 +29,16 @@ var testDatasourceInvalidMethod string
 
 func TestHttpDataSource(t *testing.T) {
 	tests := []struct {
-		Name    string
-		Path    string
-		Error   bool
-		Outputs map[string]string
+		Name            string
+		Path            string
+		Error           bool
+		ExpectedOutputs map[string]string
 	}{
 		{
 			Name:  "basic_test",
 			Path:  testDatasourceBasic,
 			Error: false,
-			Outputs: map[string]string{
+			ExpectedOutputs: map[string]string{
 				"url": "url is https://www.packer.io/",
 				// Check that body is not empty
 				"body": "body is true",
@@ -48,15 +48,15 @@ func TestHttpDataSource(t *testing.T) {
 			Name:  "url_is_empty",
 			Path:  testDatasourceEmptyUrl,
 			Error: true,
-			Outputs: map[string]string{
+			ExpectedOutputs: map[string]string{
 				"error": "the `url` must be specified",
 			},
 		},
 		{
 			Name:  "method_is_invalid",
 			Path:  testDatasourceInvalidMethod,
 			Error: true,
-			Outputs: map[string]string{
+			ExpectedOutputs: map[string]string{
 				"error": "the `method` must be one of \\[HEAD GET POST PUT DELETE OPTIONS PATCH\\]",
 			},
 		},
@@ -88,7 +88,7 @@ func TestHttpDataSource(t *testing.T) {
 						}
 					}
 
-					if tt.Outputs != nil {
+					if tt.ExpectedOutputs != nil {
 						logs, err := os.Open(logfile)
 						if err != nil {
 							return fmt.Errorf("Unable find %s", logfile)
@@ -101,7 +101,7 @@ func TestHttpDataSource(t *testing.T) {
 						}
 						logsString := string(logsBytes)
 
-						for key, val := range tt.Outputs {
+						for key, val := range tt.ExpectedOutputs {
 							if matched, _ := regexp.MatchString(val+".*", logsString); !matched {
 								t.Fatalf(
 									"logs doesn't contain expected log %v with value %v in %q",