redefine shared examples outside of rspec as toplevel, removes deprecation
fix build when run in certain ordering

TIL SharedExampleGroups aren't world safe (i.e. contained to the
world), this is a temporary fix to allow the build to pass regardless
of order, but I'm going to refactor this at some point
Change log entry
[skip ci]
Merge pull request #1023 from rspec/fix_toplevel_definition_in_modules

deprecation warnings when spec enclosed in a module