Ignore dist dir when linting

[cinaglia]

I happened to notice that the build is currently failing due to the dist/
directory not being ignored when running standard.

Happy to change the approach to use a whitelist instead of an ignore list. This could be achieved by running standard *.js test/**/*.js.

[coveralls]

Coverage remained the same at 100.0% when pulling ea3c60c on cinaglia:fix-build into e7740a4 on jimf:master.

[jimf]

Thanks!