Use gwpy for all handling of time and frequency series

Could we change all frequency_array and time_array handling to use gwpy.TimeSeries

This would simply a lot of the code. As an example, this piece of code downloads the open data into a time series and takes an FFT turning it into a FrequencySeries object.

ldata = TimeSeries.fetch_open_data('L1', 1126259446, 1126259478)
ldata_FFT = ldata.fft()

The TimeSeries and FrequencySeries object contain information about the sampling frequency and more. Realistically, we could replace much of nfft and other things that are being passed around and we get all the filtering magic which comes for free. Is there any reason not to do this?