Fix travis (#1306)

* fix dead code warning

* fix some tests by updating the language version
diff --git a/pkgs/test/test/runner/runner_test.dart b/pkgs/test/test/runner/runner_test.dart
index 8f8711c..224fdc2 100644
--- a/pkgs/test/test/runner/runner_test.dart
+++ b/pkgs/test/test/runner/runner_test.dart
@@ -731,7 +731,7 @@
     test('sound null safety is enabled if the entrypoint opts in explicitly',
         () async {
       await d.file('test.dart', '''
-// @dart=2.9
+// @dart=2.10
 $_testContents
 ''').create();
       var test = await runTest(['test.dart']);
@@ -771,7 +771,7 @@
         var newPackageConfig = PackageConfig([
           ...currentPackageConfig.packages,
           Package('example', Uri.file('${d.sandbox}/'),
-              languageVersion: LanguageVersion(2, 9),
+              languageVersion: LanguageVersion(2, 10),
               // TODO: https://github.com/dart-lang/package_config/issues/81
               packageUriRoot: Uri.file('${d.sandbox}/')),
         ]);
diff --git a/pkgs/test_api/lib/src/remote_listener.dart b/pkgs/test_api/lib/src/remote_listener.dart
index e441b99..621726c 100644
--- a/pkgs/test_api/lib/src/remote_listener.dart
+++ b/pkgs/test_api/lib/src/remote_listener.dart
@@ -76,11 +76,7 @@
             return;
           }
 
-          if (main is! Function) {
-            _sendLoadException(
-                channel, 'Top-level main getter is not a function.');
-            return;
-          } else if (main is! Function()) {
+          if (main is! Function()) {
             _sendLoadException(
                 channel, 'Top-level main() function takes arguments.');
             return;