Remove references to service in campfire model spec

spec/models/integrations/campfire_spec.rb

@@ -11,7 +11,7 @@ RSpec.describe Integrations::Campfire do
   end
 
   describe 'Validations' do
-    context 'when service is active' do
+    context 'when integration is active' do
       before do
         subject.active = true
       end
@@ -19,7 +19,7 @@ RSpec.describe Integrations::Campfire do
       it { is_expected.to validate_presence_of(:token) }
     end
 
-    context 'when service is inactive' do
+    context 'when integration is inactive' do
       before do
         subject.active = false
       end