Update Ember to 3.1

app/styles/bourbon/_bourbon-deprecate.scss

@@ -0,0 +1,19 @@
+@charset "UTF-8";
+
+/// Throws Sass warnings to announce library deprecations. You can disable them
+/// by setting the `$output-bourbon-deprecation-warnings` variable to `false`.
+///
+/// @access private
+
+@mixin _bourbon-deprecate($feature, $message: null) {
+  @if $output-bourbon-deprecation-warnings == true {
+    @warn "[Bourbon] [Deprecation] `#{$feature}` is deprecated and will be " +
+      "removed in 5.0.0. #{$message}";
+    @content;
+  }
+}
+
+@mixin _bourbon-deprecate-for-prefixing($feature) {
+  @include _bourbon-deprecate($feature, "We suggest using an automated " +
+    "prefixing tool, like Autoprefixer.");
+}