add isNaN and isNotNaN to matchers

BUG= https://code.google.com/p/dart/issues/detail?id=19302
R=kevmoo@google.com

Review URL: https://codereview.chromium.org//332663002

Patch from Sam Rawlins <srawlins@google.com>.

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/matcher@38745 260f80e4-7a28-3924-810f-c04153c831b5
4 files changed
tree: c985a6727834b6ffb90430542a0790b0f1c7112e
  1. CHANGELOG.md
  2. LICENSE
  3. README.md
  4. lib/
  5. pubspec.yaml
  6. test/
README.md

Support for specifying test expectations, such as for unit tests.

The matcher library provides a third-generation assertion mechanism, drawing inspiration from Hamcrest.

For more information, see Unit Testing with Dart.