Update CE specific specs to match CE version

The following specs don't match their versions in CE:
- `spec/services/wiki_pages/create_service_spec.rb`
- `spec/services/wiki_pages/destroy_service_spec.rb`
- `spec/services/wiki_pages/update_service_spec.rb`

There's actually no difference in logic as they work
the same way. But there's difference in how they were
written.

To ensure that there'll be no conflicts, the CE version
of the said specs has been copy-pasted to overwrite the
EE version.

spec/services/wiki_pages/create_service_spec.rb

@@ -15,7 +15,7 @@ describe WikiPages::CreateService do
   subject(:service) { described_class.new(project, user, opts) }
 
   before do
-    project.add_maintainer(user)
+    project.add_developer(user)
   end
 
   describe '#execute' do
@@ -23,11 +23,14 @@ describe WikiPages::CreateService do
       page = service.execute
 
       expect(page).to be_valid
-      expect(page).to have_attributes(title: opts[:title], content: opts[:content], format: opts[:format].to_sym)
+      expect(page.title).to eq(opts[:title])
+      expect(page.content).to eq(opts[:content])
+      expect(page.format).to eq(opts[:format].to_sym)
     end
 
     it 'executes webhooks' do
-      expect(service).to receive(:execute_hooks).once.with(instance_of(WikiPage), 'create')
+      expect(service).to receive(:execute_hooks).once
+        .with(instance_of(WikiPage), 'create')
 
       service.execute
     end

spec/services/wiki_pages/destroy_service_spec.rb

@@ -8,12 +8,13 @@ describe WikiPages::DestroyService do
   subject(:service) { described_class.new(project, user) }
 
   before do
-    project.add_maintainer(user)
+    project.add_developer(user)
   end
 
   describe '#execute' do
     it 'executes webhooks' do
-      expect(service).to receive(:execute_hooks).once.with(instance_of(WikiPage), 'delete')
+      expect(service).to receive(:execute_hooks).once
+        .with(instance_of(WikiPage), 'delete')
 
       service.execute(page)
     end

spec/services/wiki_pages/update_service_spec.rb

@@ -17,7 +17,7 @@ describe WikiPages::UpdateService do
   subject(:service) { described_class.new(project, user, opts) }
 
   before do
-    project.add_maintainer(user)
+    project.add_developer(user)
   end
 
   describe '#execute' do
@@ -25,13 +25,15 @@ describe WikiPages::UpdateService do
       updated_page = service.execute(page)
 
       expect(updated_page).to be_valid
-      expect(updated_page).to have_attributes(message: opts[:message], content: opts[:content], format: opts[:format].to_sym)
-
+      expect(updated_page.message).to eq(opts[:message])
+      expect(updated_page.content).to eq(opts[:content])
+      expect(updated_page.format).to eq(opts[:format].to_sym)
       expect(updated_page.title).to eq(opts[:title])
     end
 
     it 'executes webhooks' do
-      expect(service).to receive(:execute_hooks).once.with(instance_of(WikiPage), 'update')
+      expect(service).to receive(:execute_hooks).once
+        .with(instance_of(WikiPage), 'update')
 
       service.execute(page)
     end