Prevent example groups named "Config" from generating a deprecation warning.
Merge pull request #1580 from jimmycuadra/avoid-config-warning

Prevent example groups named "Config" from generating a deprecation warning
changelog for #1580
Add an additional spec for the first from #1580.

The spec added in #1580 is a bit implicit in that
it depends upon RbConfig issuing a warning, which
may not always be the case in all versions of ruby.
The basic problem is that we were not ignoring top
level constants, so this added spec makes that
more explicit, and we can count on `Hash` always
being a top level constant even if RbConfig doesn’t
always issue the warning.
Merge pull request #1594 from rspec/add-extra-spec-for-1580

Add an additional spec for the first from #1580.
Use maintenance branch in the Gemfile.
Merge pull request #1597 from rspec/use-maint-branch-master

Use maintenance branch in the Gemfile.
Fix color on Shared Example Group failure.

Now is white to separate it from the stack trace.
Add a changelog entry for #1593
Pass the colorizer around correctly in Failure Notification.
Color Proc injection