Merge pull request #1 from eksoverzero/my_version_2

My version 2
Ensure redis configuration is actually changed for each instance.

The redis connection is memoized as a class-instance variable on `Sidekiq`.
This means that setting the redis configuration has no effect after the first
time within the same process.

It looks as if the NewRelic gem runs all plugins in the same process, so we
need to reset the redis configuration somehow. I can't see a clean way of
doing this with the existing `Sidekiq` API, so this hack will have to do
for now.
Return the exact error if something goes wrong.
Merge pull request #3 from mariozaizar/master

Return the exact error if something goes wrong.
Merge pull request #2 from Futurelearn/reset-redis-configuration-for-each-instance

Ensure redis configuration is actually changed for each instance.
guid changed to republish on New Relic. Long story.
changes agent guid
Update newrelic_sidekiq_agent
Update newrelic_sidekiq_agent
more specs