Allow deeper group nesting in RSpec

[no-reply]

The reason for restricting nesting is presumably to flag complex test setups
that indicate a smell in the tested code. Three levels are
allowed
to accomodate this common style:

describe MyClass do
  describe '#a_method' do
    context 'some application state' do
      # examples
    end

    context 'other application state' do
      # examples
    end
  end
end

My experience has been that a slightly more complex setup in a Rails
application (particularly for model and controller specs) is more a fact of life
than a code smell. Four levels accommodates code like:

describe MyController, type: :controller do
  context 'when logged in as admin' do
    include_context 'as admin' do

    ...
  end

  context 'when logged is as other_role' do
    include_context 'as other_role' do
    ...
  end
end

Using my current application as a gague, my sense is that the additional level
of nesting addresses the common cases.