Note - this is the default for get_interferometer_with_fake_noise.., not
the default in general.

Makes the options to set the PSD methods. Retains the default behaviour
(will use aLIGO if nothing is set). But now, users must call a
`set_from_` method after initialising the PowerSpectalDensity()`.

Also adds logging messages

Previously, set_from_frame not only loaded in the time domain data, but
also applied a filter and FFT'd. This is no longer required and has
hence been removed.

- Fix error in create psd
- Fix minimum and maximum frequencies
- Improve documentation

Adds functions to set the strain data from open data, generate a PSD,
filter, and window.

- Adds a time_array and time_domain_strain to the
  InterferometerStrainData
- Adds a test for consistency between the time and frequency domain
  strain

- Adds a specific function to work out whether the frequency_array or
sampling frequency and duration where given
- General pep8 clean up
- No changes to functionality

- Provides backward compatibility for people with scripts using the old
  style
- Also because, as Colm pointed out, there may be bugger behaviour with
  multiple detectors and it may take a long time to calculate the waveform
- Change the name in `inject_signal` from
  waveform_polarizations->injection_polarizations.

This last step could break peoples code who are using inject_signal
directly, but its probably best to unify notation now rather than have
two names for one thing.

Also makes the filter_freq and alpha explicit so its easier to see where
these are set.

Closes #116

- Changes the warning to an Error
- Adds method to InterferometerStrainData to check if a time is within
  the span
- Clean up logging of warning if the geocent_time is within the data
  span
- Print infomation about the injection to the terminal

Closes #115

Adds the option to add a label to the saved data and plots associated
with Interferometer

Implemented append, extend, insert methods from super class with a check that makes sure that the interferometers stay consistent.