Upgrade to amqp 1.x

[nsweeting]

This upgrades the amqp package to the latest version - 1.1.

The migration guide is available here: https://github.com/pma/amqp/wiki/Upgrade-from-0.X-to-1.0

On upgrade, some issues related to lager pop up. These were dealt with following the recommendations here: https://github.com/pma/amqp#troubleshooting--faq

So far - the tests pass. But as mentioned in the migration guide - that may not be enough of a bar to pass. Individuals more familiar with the internals of TaskBunny might be able to provide further insight.

Related to #70

[IanLuites]

Thank you for the PR!

We're going to have a look, but it might take a while, since the pattern matching [might] change current behavior and we noticed some of the code/formatting is really outdated, while we were reviewing.

(Not the code you added, but the code in general, since last time we properly touched it was back on Elixir 1.4)

[nsweeting]

Sounds good @IanLuites. Thanks for the update. Perhaps we can sort out any behaviour conflicts that might occur from the amqp update, then create a new PR to run the formatter on the codebase?

[christianjgreen]

Should this be adding pattern matching? I feel like it's best to pass the result through rather than raising a MatchError.

This is also the behavior that is currently in 0.3.1 https://github.com/pma/amqp/blob/c1148673a8a909b3b4412c77aba7ff252c7576e8/lib/amqp/basic.ex#L314

[nsweeting]

From what I understand, this PR just matches existing behaviour. The older version of AMQP would simply raise a MatchError itself. Whereas here - it will be raised within TaskBunny. Obviously - there are more elegant solutions to handling the errors. I just wanted to focus on the upgrade while maintaining existing behaviour first.