use different logger for async notices

fix rake test task for async
closes airbrake#119

lib/airbrake/configuration.rb

@@ -251,13 +251,10 @@ def async(&block)
     end
     alias_method :async?, :async
 
-    def async=(value)
-      # use default GirlFriday-async for 'true' value
-      @async = if value == true
-                 default_async_processor
-               else
-                 value
-               end
+    def async=(use_default_or_this)
+      @async = use_default_or_this == true ?
+        default_async_processor :
+        use_default_or_this
     end
 
     def js_api_key

lib/airbrake/rails3_tasks.rb

@@ -8,6 +8,18 @@
       ActiveSupport::TaggedLogging.new(Logger.new(STDOUT)) :
       Logger.new(STDOUT)
 
+    def wait_for_threads
+      # if using multiple threads, we have to wait for
+      # them to finish
+      if GirlFriday.status.empty?
+        Thread.list.each do |thread|
+          thread.join unless thread == Thread.current
+        end
+      else
+        GirlFriday.shutdown!
+      end
+    end
+
     Rails.logger.level = Logger::DEBUG
     Airbrake.configure(true) do |config|
       config.logger = Rails.logger
@@ -80,5 +92,7 @@ class AirbrakeVerificationController < ApplicationController; end
     env = Rack::MockRequest.env_for("/verify")
 
     Rails.application.call(env)
+
+    wait_for_threads
   end
 end

lib/airbrake/railtie.rb

@@ -15,7 +15,7 @@ class Railtie < ::Rails::Railtie
 
     config.after_initialize do
       Airbrake.configure(true) do |config|
-        config.logger           ||= ::Rails.logger
+        config.logger           ||= config.async? ? ::Logger.new(STDERR) : ::Rails.logger
         config.environment_name ||= ::Rails.env
         config.project_root     ||= ::Rails.root
         config.framework        = "Rails: #{::Rails::VERSION::STRING}"