Initial check-in

Template for all aoc days

aoc2020/test/aoc2020_test.dart

@@ -0,0 +1,8 @@
+// import 'package:aoc2020/aoc2020.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('calculate', () {
+    // expect(calculate(), 42);
+  });
+}