Add support of mixed-type array (#376)

Fixes #357

parser_test.go

@@ -488,18 +488,6 @@ func TestNestedEmptyArrays(t *testing.T) {
 	})
 }
 
-func TestArrayMixedTypes(t *testing.T) {
-	_, err := Load("a = [42, 16.0]")
-	if err.Error() != "(1, 10): mixed types in array" {
-		t.Error("Bad error message:", err.Error())
-	}
-
-	_, err = Load("a = [42, \"hello\"]")
-	if err.Error() != "(1, 11): mixed types in array" {
-		t.Error("Bad error message:", err.Error())
-	}
-}
-
 func TestArrayNestedStrings(t *testing.T) {
 	tree, err := Load("data = [ [\"gamma\", \"delta\"], [\"Foo\"] ]")
 	assertTree(t, tree, err, map[string]interface{}{
@@ -934,7 +922,7 @@ func TestTomlValueStringRepresentation(t *testing.T) {
 		{[]interface{}{"gamma", "delta"}, "[\"gamma\",\"delta\"]"},
 		{nil, ""},
 	} {
-		result, err := tomlValueStringRepresentation(item.Value, "", "", false)
+		result, err := tomlValueStringRepresentation(item.Value, "", "", OrderPreserve, false)
 		if err != nil {
 			t.Errorf("Test %d - unexpected error: %s", idx, err)
 		}