Fixed select failures in regressions tests

no issue

- a couple of regressions tests would repeatedly fail on CI. They would
  always follow tests that closed the Ghost server beforehand.
- this commit doesn't close the server after those tests have completed,
  which is similar functionality to all other tests
- the actual cause is unknown at this point, but I suspect it's some
  sort of race condition

core/test/regression/api/canary/admin/settings_spec.js

@@ -21,10 +21,6 @@ describe('Settings API (canary)', function () {
                 });
         });
 
-        after(function () {
-            return ghostServer.stop();
-        });
-
         it('Can\'t read core setting', function () {
             return request
                 .get(localUtils.API.getApiQuery('settings/db_hash/'))

core/test/regression/api/v2/admin/settings_spec.js

@@ -21,10 +21,6 @@ describe('Settings API (v2)', function () {
                 });
         });
 
-        after(function () {
-            return ghostServer.stop();
-        });
-
         it('Can\'t read core setting', function () {
             return request
                 .get(localUtils.API.getApiQuery('settings/db_hash/'))

core/test/regression/api/v3/admin/settings_spec.js

@@ -20,10 +20,6 @@ describe('Settings API', function () {
             });
     });
 
-    after(function () {
-        return ghostServer.stop();
-    });
-
     it('Can\'t read core setting', function () {
         return request
             .get(localUtils.API.getApiQuery('settings/db_hash/'))