Blacklisted queues should not send general metrics

When the middleware is called and a blacklisted queue is referenced,
we should short-circuit processing altogether and not even query/report 
the general set of metrics.

lib/librato-sidekiq/middleware.rb

@@ -60,7 +60,7 @@ def call(worker_instance, msg, queue, redis_pool = nil)
         result = yield
         elapsed = (Time.now - start_time).to_f
 
-        return result unless enabled
+        return result unless enabled && allowed_to_submit(queue, worker_instance)
         # puts "#{worker_instance} #{queue}"
 
         stats = ::Sidekiq::Stats.new
@@ -76,7 +76,6 @@ def call(worker_instance, msg, queue, redis_pool = nil)
 
       def track(tracking_group, stats, worker_instance, msg, queue, elapsed)
         submit_general_stats tracking_group, stats
-        return unless allowed_to_submit queue, worker_instance
         # puts "doing Librato insert"
         tracking_group.group queue.to_s do |q|
           q.increment 'processed'

spec/unit/client_middleware_spec.rb

@@ -87,11 +87,8 @@
         middleware.blacklist_queues << queue_name
       end
 
-      it { expect { |b| middleware.call(some_worker_instance, some_message, queue_name, &b) }.to yield_with_no_args }
-
-      it 'should measure increment queued metric' do
-        expect(meter).to receive(:increment).with 'queued'
-        middleware.call(some_worker_instance, some_message, queue_name) {}
+      it 'should not send any metrics' do
+        Librato.should_not_receive(:group)
       end
 
     end

spec/unit/middleware_spec.rb

@@ -87,20 +87,8 @@
         middleware.blacklist_queues << queue_name
       end
 
-      it { expect { |b| middleware.call(some_worker_instance, some_message, queue_name, &b) }.to yield_with_no_args }
-
-      it 'should measure increment processed metric' do
-        expect(meter).to receive(:increment).with "processed"
-        middleware.call(some_worker_instance, some_message, queue_name) {}
-      end
-
-      it 'should measure general metrics' do
-        {"enqueued" => 1, "failed" => 2, "scheduled" => 3 }.each do |method, stat|
-          expect(meter).to receive(:measure).with(method.to_s, stat)
-        end
-        expect(meter).to receive(:increment).with "processed"
-
-        middleware.call(some_worker_instance, some_message, queue_name) {}
+      it 'should not send any metrics' do
+        Librato.should_not_receive(:group)
       end
 
     end