Allow code coverage report

pub global run coverage:collect_coverage --port=8111 -o coverage.json --resume-isolates --wait-paused &
dart --observe=8111 test/rxdart_test.dart &
pub global run coverage:format_coverage --package-root=packages --report-on lib --in coverage.json --out lcov.info --lcov

test/dart_kollection_test.dart

@@ -0,0 +1,20 @@
+import 'collection/iterable_extensions_test.dart' as iterable_extensions_test;
+import 'collection/list_mutable_test.dart' as list_mutable_test;
+import 'collection/list_test.dart' as list_test;
+import 'collection/map_empty_test.dart' as map_empty_test;
+import 'collection/map_extensions_test.dart' as map_extensions_test;
+import 'collection/map_test.dart' as map_test;
+import 'collection/set_test.dart' as set_test;
+import 'collections_test.dart' as collections_test;
+
+main() {
+  collections_test.main();
+  iterable_extensions_test.main();
+  list_test.main();
+  list_mutable_test.main();
+  list_test.main();
+  map_empty_test.main();
+  map_extensions_test.main();
+  map_test.main();
+  set_test.main();
+}