Update Ember to 3.1

app/styles/neat/grid/_shift.scss

@@ -0,0 +1,50 @@
+@charset "UTF-8";
+
+/// Translates an element horizontally by a number of columns. Positive arguments shift the element to the active layout direction, while negative ones shift it to the opposite direction.
+///
+/// @param {Number (unitless)} $n-columns [1]
+///   Number of columns by which the element shifts.
+///
+/// @example scss - Usage
+///   .element {
+///     @include shift(-3);
+///   }
+///
+/// @example css - CSS output
+///   .element {
+///     margin-left: -25.58941%;
+///   }
+
+@mixin shift($n-columns: 1) {
+  @include shift-in-context($n-columns);
+}
+
+/// Translates an element horizontally by a number of columns, in a specific nesting context.
+///
+/// @param {List} $shift
+///   A list containing the number of columns to shift (`$columns`) and the number of columns of the parent element (`$container-columns`).
+///
+///   The two values can be separated with any string such as `of`, `/`, etc.
+///
+/// @example scss - Usage
+///   .element {
+///     @include shift(-3 of 6);
+///   }
+///
+/// @example css - CSS output
+///   .element {
+///     margin-left: -52.41458%;
+///   }
+
+@mixin shift-in-context($shift: $columns of $container-columns) {
+  $n-columns: nth($shift, 1);
+  $parent-columns: container-shift($shift) !global;
+
+  $direction: get-direction($layout-direction, $default-layout-direction);
+  $opposite-direction: get-opposite-direction($direction);
+
+  margin-#{$opposite-direction}: $n-columns * flex-grid(1, $parent-columns) + $n-columns * flex-gutter($parent-columns);
+
+  // Reset nesting context
+  $parent-columns: $grid-columns !global;
+}