Merge pull request neysimoes#3 from raphaelfabeni/master

Add new mixins

Author: neysimoes

README.md

@@ -3,10 +3,139 @@ SASS Mixins
 
 A collection of [SASS](http://sass-lang.com/ "SASS") mixins for your project.
 
-* Box shadow
-* Opacity
-* Clearfix
-* Border radius
-* Box-sizing
-* Transition
-* Animation
+* [Animation](#animation)
+   * [Keyframes](#keyframes)
+* [Background size](#background-size)
+* [Box shadow](#box-shadow)
+* [Opacity](#opacity)
+* [Clearfix](#clearfix)
+* [Border radius](#border-radius)
+* [Box-sizing](#box-sizing)
+* [Transition](#transition)
+* [Columns](#columns)
+* [Transform](#transform)
+    * [Default](#default)
+    * [Translate](#translate)
+    * [Skew](#skew)
+    * [Scale](#scale)
+    * [Rotate](#rotate)
+    * [Transform-origin](#transform-origin)
+* [Gradients](#gradients)
+    * [Linear Horizontal](#linear-horizontal)
+    * [Linear Vertical](#linear-vertical)
+
+## Animation
+
+```scss
+.class { @include animation(animationName 1s); }
+```
+
+### Keyframes
+
+```scss
+@include keyframes(animationOne) {
+    from { background-color: red; }
+    to { background-color: black; }
+}
+```
+
+## Background size
+
+```scss
+.class { @include background-size(auto 100%); }
+```
+
+## Box shadow
+
+```scss
+.class { @include box-shadow(1px 1px 10px 10px #666, 2px 2px 5px 5px #ddd inset); }
+```
+
+## Opacity
+
+```scss
+.class { @include opacity(0.5); }
+```
+
+## Clearfix
+
+```scss
+.class { @include clearfix(); }
+```
+
+## Border-radius
+
+```scss
+.class { @include border-radius(10px); }
+```
+
+## Box-sizing
+
+```scss
+.class { @include box-sizing(); }
+```
+
+## Transition
+
+```scss
+.class { @include transition(color 1s .5s ease-out); }
+```
+
+## Columns
+
+```scss
+.class { @include columns(3, 150px, solid 1px red); }
+```
+
+## Transform
+
+### Default
+
+```scss
+.class { @include transform(rotate(45deg); }
+```
+
+### Translate
+
+```scss
+.class { @include translate(100px, 100px); }
+```
+
+### Skew
+
+```scss
+.class { @include skew(10px, 10px); }
+```
+
+### Scale
+
+```scss
+.class { @include scale(0.75); }
+```
+
+### Rotate
+
+```scss
+.class { @include rotate(45deg); }
+```
+
+### Transform-origin
+
+```scss
+.class { @include transform-origin(left, top); }
+```
+
+## Gradients
+
+### Linear horizontal
+
+```scss
+.class { @include horizontal-gradient(#666, #000); }
+```
+
+### Linear vertical
+
+```scss
+.class { @include vertical-gradient(#666, #000); }
+```
+