test: update test file

Author: drawcall

lib/src/core/context.dart

@@ -1,5 +1,5 @@
-import 'dart:ui' as ui;
 import "dart:math";
+import 'dart:ui' as ui;
 import 'package:flutter/widgets.dart';
 import '../math/point.dart';
 import '../math/mathutil.dart';

test/widget_test.dart

@@ -7,8 +7,7 @@
 
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
-
-import 'package:zerker/zerker.dart';
+import '../lib/zerker.dart';
 
 void main() {
   testWidgets('Counter increments smoke test', (WidgetTester tester) async {