Cop idea: Don't use remove_const in specs

[swelther]

We had some specs in our project that used Object.send(:remove_const, :SomeConstant) instead of using e.g. stub_const. This lead to annoying and hard to debug issues in our CI pipelines. To get rid of these usages and rise awareness about this we created a cop that we would like to contribute, if you are interested.

# bad
it 'does something' do
  Object.send(:remove_const, :SomeConstant)
end

# bad
before do
  Object.send(:remove_const, :SomeConstant)
end

[pirj]

Makes sense. A PR is welcome.