Don't specify percentage unit for zero values
Merge pull request #1 from unfold/master

Don't specify percentage unit for zero values
testing via `npm test` now works and travis ci is setup
added travis status image - visionmedia needs to turn on travis first, though
removed empty file
upgraded stylus
added additional vendor prefixes, made min-device-pixel-ratio adjustable, and fixed the image.styl test
patch up test to match #156
fixed change in order of rules introduced by #156
added official prefix for tab-size and added test - closes #172
Merge pull request #195 from visionmedia/stuff

relatively small amount of stuff