flex-sass-mixins

Clean sass mixins for cross-browser and fallback flex.
There are other mixins for flexbox using SASS, but this one is better.
Also it is based on @mmcbride1007's flexbox-mixins for LESS.

How to use

1. Copy `_flex.scss` into your styles directory 2. Be sure to import the file into your project with either an `@import` or a `link` in the head 3. These mixins stick to the original class declarations of flex with few shortcuts, so all you have to do is: ```scss .class{ @include flex-display(); } ``` and then...$$$.