handle queue returns only message body

[ghost]

This should close issue #62.

Changes:

• handle-queue only returns body of received messages, therefore:
• added bond library
• test-fixtures now holds an exposed test-handler-fn to be spied on in tests
• core-test now uses bond to spy on above handler function for passed arguments

Notes: I would have liked to verify that the message has (not) been deleted in done-fn-handle-present-when-auto-delete-false and done-fn-handle-present-when-auto-delete-true but with this change I cannot get the message ID anymore (because its not returned anymore) to delete the message manually via sqs/delete-message afterwards. Neither can I call the done-fn handle directly anymore. In case you have an idea here I'm all ears.

[Quantisan]

as noted on Slack, core-test and test-fixture is showing unnecessary complexity because of https://github.com/Motiva-AI/clj-sqs-extended/issues/13 I'll let it pass for v0.1 as we're pushing a delivery date.

let's go back to it on v0.2 to tidy up. it's easier if I show some code examples.