Windows: Found 0 matching tests

I tried to run example with sum under windows 7, but i have the following message:
`Found 0 matching tests`.

Problem exists because here: https://github.com/facebook/jest/blob/master/src/TestRunner.js#L122 regexp always return false.

Why? Because on windows directory separator is `\` and on some other systems it is `/`, so some regexps (https://github.com/facebook/jest/blob/master/src/TestRunner.js#L78, https://github.com/facebook/jest/blob/master/bin/jest.js#L198) always gives false.