clean(): removed trailing whitespce

public/sass/mixins/_animations.scss

@@ -4,13 +4,13 @@
     }
     @-moz-keyframes #{$animation-name} {
         @content;
-    }  
+    }
     @-ms-keyframes #{$animation-name} {
         @content;
     }
     @-o-keyframes #{$animation-name} {
         @content;
-    }  
+    }
     @keyframes #{$animation-name} {
         @content;
     }
@@ -21,5 +21,5 @@
   -moz-animation: #{$str};
   -ms-animation: #{$str};
   -o-animation: #{$str};
-  animation: #{$str};      
+  animation: #{$str};
 }