Multiple bindings which only differ in binding arguments not working correctly

[hjohn]

We discovered that when creating two queue bindings on the same exchange which only differ in binding arguments that rabbit mock will not deliver messages to the queue for all of the possible bindings (ie, one of the bindings simply does not work despite a message being delivered to the exchange with correct arguments).

This is because the BindConfigurations are at some point compared and its equals/hashCode does not take the binding arguments into account.

PR #228 shows a potential solution which fixes our test cases.