Remove memoization of Channel objects

Unnecessary memory leak

lib/pusher/client.rb

@@ -111,8 +111,7 @@ def webhook(request)
     #   configured
     def [](channel_name)
       raise ConfigurationError, 'Missing client configuration: please check that key, secret and app_id are configured.' unless configured?
-      @channels ||= {}
-      @channels[channel_name.to_s] ||= Channel.new(url, channel_name, self)
+      Channel.new(url, channel_name, self)
     end
 
     # Request a list of occupied channels from the API

spec/client_spec.rb

@@ -155,12 +155,6 @@
           @channel.should be_kind_of(Pusher::Channel)
         end
 
-        it "should reuse the same channel objects" do
-          channel1, channel2 = @client['test_channel'], @client['test_channel']
-
-          channel1.object_id.should == channel2.object_id
-        end
-
         %w{app_id key secret}.each do |config|
           it "should raise exception if #{config} not configured" do
             @client.send("#{config}=", nil)