Declaring an exchange with no permission should be handled better

[fetep]

NoMethodError: undefined method `payload' for nil:NilClass
next_payload at /home/petef/.rvm/gems/jruby-1.6.0/gems/bunny-0.6.0/lib/qrack/client.rb:84
open_connection at /home/petef/.rvm/gems/jruby-1.6.0/gems/bunny-0.6.0/lib/bunny/client08.rb:210
start_session at /home/petef/.rvm/gems/jruby-1.6.0/gems/bunny-0.6.0/lib/bunny/client08.rb:397
loop at org/jruby/RubyKernel.java:
start_session at /home/petef/.rvm/gems/jruby-1.6.0/gems/bunny-0.6.0/lib/bunny/client08.rb:389
(root) at bunny-bug.rb:7

This happens when you try connecting with a valid username/password, but one that has no permissions on the vhost in question. To reproduce, here's the code:

b = Bunny.new({:vhost => "/test", :user => "guest", :pass => "guest"})
b.start
e = b.exchange("rawlogs", :type => "direct")

and assuming rabbitmq, you'll need to "rabbitmqctl add_vhost /test" to create the vhost. By default, the "guest" user will not have access to create exchanges under /test.

Expected behavior: a Bunny:: exception with a better error message

[botanicus]

BTW this is the very same one as celldee#21 I'm on it now.

[botanicus]

Should work now, it does for me at least. If you can check it, that'd be groovy.