v1.2.0-canary.6

• Add system-ui to default font stack (#1326)
• Add shadow-xs, increase shadow-sm alpha to 0.05 (#1333)
• Support import syntax even without postcss-import (#1336)
• Alias tailwind bin to tailwindcss (e988185)
• Add fill/stroke to transition-colors (#1351)
• Add transition-shadow, add box-shadow to default transition (#1352)
• Combine gap/columnGap/rowGap (#1353)
• Add grid row utilities (#1355)
• Add skew utilities (#1356)
• Use font-sans as default font (#1357)