UX: New group membership management workflow.

https://meta.discourse.org/t/adding-owners-members-ux-is-inconsistent-and-misleading/58084

test/javascripts/acceptance/group-index-test.js.es6

@@ -9,6 +9,11 @@ QUnit.test("Viewing Members as anon user", assert => {
     assert.ok(count('.avatar-flair .fa-adjust') === 1, "it displays the group's avatar flair");
     assert.ok(count('.group-members tr') > 0, "it lists group members");
 
+    assert.ok(
+      count('.group-navigation-dropdown') === 0,
+      'it should not display the group navigation dropdown menu'
+    );
+
     assert.ok(
       count('.group-member-dropdown') === 0,
       'it does not allow anon user to manage group members'
@@ -29,6 +34,11 @@ QUnit.test("Viewing Members as an admin user", assert => {
   visit("/groups/discourse");
 
   andThen(() => {
+    assert.ok(
+      count('.group-navigation-dropdown') === 1,
+      'it should display the group navigation dropdown menu'
+    );
+
     assert.ok(
       count('.group-member-dropdown') > 0,
       'it allows admin user to manage group members'