Merge pull request #443 from newrelic/374-changelog

Draft CHANGELOG for 3.7.4
Merge branch 'dev' into release
Merge remote-tracking branch 'origin/dev' into release
Merge remote-tracking branch 'origin/dev' into release
Merge branch 'dev' into release
Merge branch 'dev' into release
Merge branch 'dev' into release
Merge branch 'dev' into release
Merge branch 'dev' into release
RUBY-1294 Disable mongo instrumentation on version 1.10+ of the mongo gem

This is a temporary measure until we're able to add instrumentation support for
this version of the mongo gem.
RUBY-1294 Clarify comments in mongo Envfile about which versions are supported
Merge pull request #472 from ruby-agent/RUBY-1294-mongo-crash

RUBY-1294 Disable mongo instrumentation on version 1.10+ of the mongo gem
Do not ruby mongo-1.10.0 tests on JRuby, since the gem is busted there
Merge pull request #473 from ruby-agent/exclude-mongo-110-on-jruby

Do not ruby mongo-1.10.0 tests on JRuby, since the gem is busted there
Merge remote-tracking branch 'origin/release' into dev
Merge in updates to config docs there were made on the docs site but never integrated to the Ruby agent
Merge pull request #474 from ruby-agent/merge-in-config-doc-updates

Merge in updates to config docs there were made on the docs site but never integrated to the Ruby agent
Move recorded_metrics to the Transaction class.
Add pry-nav gem as a development dependency (commented).

I'd like to easily be able to turn on pry-nav, but it makes multiverse[mongo]
hang. So I'm adding it, but leaving it commented out.
Tiny changes (cosmetic).