clear up IQ generation adn virtual channel generation

pulse_lib/IQ_virt_chan_constructor.py

pulse_lib/base_pulse.py

pulse_lib/segments/__pycache__/segments_IQ.cpython-37.pyc

pulse_lib/segments/__pycache__/segments_base.cpython-37.pyc

pulse_lib/segments/data_classes/data_generic.py

pulse_lib/segments/segment_base.py

pulse_lib/segments/segment_container.py

pulse_lib/segments/segment_markers.py

pulse_lib/segments/test.py

pulse_lib/virtual_channel_constructors.py