Run tests more similar to how CI runs them
Use istanbul for optional code coverage

Run tests with coverage with 'npm test --coverage', or run 'npm run coverage'
to first run tests with coverage and then generate coverage reports in the
coverage/ directory.
Ignore CI related files
Merge pull request #9 from strongloop/feature/ci-cleanup

* Makes test scripts more compatible with CI by exposing mocha params
* Replaces `./run-coverage` using `blanket` with `npm run coverage` using `istanbul`
* Makes sure extra files aren't packaged up by `npm pack` when run on CI