Consider handling `its` with hooks

[yujinakayama]

• Upgrade to RSpec 3.0 ruby-concurrency/concurrent-ruby#128 (comment)

Though currently I'm not sure if Transpec can determine this complex case.

[jeremywadsack]

I ran into a problem with how the its conversion works for this code:

context 'for a nil response' do
  before do
    subject.data = nil
  end

  describe '#data' do
    subject { super().data }
    it { should be_nil }
  end
end

Running rspec returned:

   Failure/Error: subject.data = blank_response
     NoMethodError:
       undefined method `data=' for false:FalseClass

Because the before is being applied after the subject is redefined.

My solution was just to change the spec to use this syntax, which actually I think is easier to read.

context 'for a nil response' do
  before do
    subject.data = nil
  end

  it { expect(subject.data).to be_nil }
end

We use this pattern pretty often such that of the 250 or so errors on a 10k-spec suite, every one of them was an instance of this.