Make functions to plot waveforms and posterior samples in time and frequency domain

Make something like:

tupak.gw.util.plot_time_domain_waveform_and_posteriors(samples, waveform, IFOs)
tupak.gw.util.plot_frequency_domain_waveform_and_posteriors(samples, waveform, IFOs)

which makes production-quality plots of the data (orange colour), maximum likelihood waveform (dark blue), and posterior samples (light blue).