Higher code quality for fork to namespace API

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 v 8.12.0 (unreleased)
-  - Add abillity to fork to a specific namespace using API. @ritave <olaf@tomalka.me>
+  - Add ability to fork to a specific namespace using API. (ritave)
   - Prepend blank line to `Closes` message on merge request linked to issue (lukehowell)
   - Filter tags by name !6121
   - Make push events have equal vertical spacing.

lib/api/projects.rb

@@ -204,7 +204,6 @@ module API
           namespace = Namespace.find_by(id: namespace_id) || Namespace.find_by_path_or_name(namespace_id)
           not_found!('Target Namespace') unless namespace
-          authorize! :create_projects, namespace
           attrs[:namespace] = namespace
         end

spec/requests/api/fork_spec.rb

@@ -3,10 +3,10 @@ require 'spec_helper'
 describe API::API, api: true  do
   include ApiHelpers
   let(:user)  { create(:user) }
-  let(:user2) { create(:user, username: 'user2_name') }
+  let(:user2) { create(:user) }
   let(:user3) { create(:user) }
   let(:admin) { create(:admin) }
-  let(:group) { create(:group, name: 'group_name') }
+  let(:group) { create(:group) }
   let(:group2) do
     group = create(:group, name: 'group2_name')
     group.add_owner(user2)
@@ -94,7 +94,7 @@ describe API::API, api: true  do
       it 'fails if trying to fork to another user when not admin' do
         post api("/projects/fork/#{project.id}", user2), namespace: admin.namespace.id
-        expect(response).to have_http_status(403)
+        expect(response).to have_http_status(409)
       end
       it 'fails if trying to fork to non-existent namespace' do
@@ -114,7 +114,7 @@ describe API::API, api: true  do
       it 'fails to fork to not owned group' do
         post api("/projects/fork/#{project.id}", user2), namespace: group.name
-        expect(response).to have_http_status(403)
+        expect(response).to have_http_status(409)
       end
       it 'forks to not owned group when admin' do