Revert "Revert Ember 2.10+ for a short while"

This reverts commit 21682fd60b92414348a0e4aecdab1bc5278e14e6.

plugins/discourse-details/assets/javascripts/initializers/apply-details.js.es6

@@ -21,6 +21,7 @@ function initializeDetails(api) {
           "details_text",
           { multiline: false }
         );
+        this.set('optionsVisible', false);
       }
     }
   });