Add initial support for building in a RHEL 7 mock

Building in an x86_64 mock, since RHEL has not yet provided a 32-bit release.
Merge pull request #156 from mckern/add-el7-for-mocks

Add initial support for building in a RHEL 7 mock
MCO-172 - fix subscription logic for rabbitmq.use_reply_exchange mode

This commit explains the reasoning behind the original
`return if type == :reply` gates in `#subscribe` and `#unsubscribe` and
the exception needed to them for the `use_reply_exchange` option.
Merge pull request #158 from richardc/mco-172

MCO-172 - fix subscription logic for rabbitmq.use_reply_exchange mode
(MCO-173) Improve logging when using STOMP 1.1 features with a gem that only supports STOMP 1.0

In the past when a stomp protocol incompatibility error occurred during
runner startup the daemon would not start and no error message would be
logged. This would however always happen if a failure occurred during
initialization of the runner.

This commit adds an exception handler to runner#initialize that will
make sure that an error message is logged when it fails to start.
Merge pull request #159 from ploubser/improvement/master/mco-173

(MCO-173) Improve logging when using STOMP 1.1 features with a gem that ...
MCO-174 update wording about wroking version of use_reply_exchange

`rabbitmq.use_reply_exchange` was broken in 2.3.3 and 2.4.0.

A fix is targeted for 2.4.1 and it shouldn't regress.
Merge pull request #160 from richardc/mco-174

MCO-174 update wording about wroking version of use_reply_exchange
maint - update changelog
Merge branch 'master' into 2.4.x