(feat) Use NoOp mode to support unit testing via rspec (macro)

[ranjib]

  let(:scheduler) do                                                          
    noop_scheduler_from_file('example_blend.rb')  
  end                                                                         
  it 'should have 3 tasks' do                                                 
    expect(scheduler.tasks.size).to eq(2)                                     
  end