add Slack notification to .travis.yml
fix intermittent build failures (maybe). closes #1407
Merge pull request #1414 from boneskull/mocha-1407

fix intermittent build failures (maybe). closes #1407
add a CONTRIBUTING.md.  closes #882
Merge pull request #1415 from boneskull/issue/882

add a CONTRIBUTING.md.  closes #882
add Slack notification to .travis.yml
fix intermittent build failures (maybe). closes #1407
add a CONTRIBUTING.md.  closes #882
Merge branch 'master' of https://github.com/mochajs/mocha