Merge pull request #8 from isao/testjs

changes from pull #7 w/out tests/fixtures

- fix error where the coverage report directory was
  removed before the report was written to it
- remove fake async code for "app" tests
- replace process.exit with callback(err, ok)
- rm dead code
- README edits
Merge pull request #9 from isao/testjs

manhattan node 0.8 doesn't have os.tmdir()