Pymwalib

* Requires mwalib 0.12.*.
* Added metafits_context.calibrator and metafits_context.calibrator_source

* Requires mwalib 0.11.*.
* Added corr_raw_scale_factor to metafits metadata.

* Requires mwalib 0.9.*.
* Added mwa_version to MetafitsContext.
* When working only with a MetafitsContext, None can be passed in lieu of an MWAVersion, and mwalib will attempt to determine the correct MWAVersion based on the MODE keyword from the metafits file.
* Added method get_expected_volt_filename() function to MetafitsContext.
* Added digital_gains, dipole_gains and dipole_delays Rfinput.
* Added receivers, delays to MetafitsContext.

* Requires mwalib 0.8.7.
* Release to fix issue with pypi deployment.
* Pymwalib now only has to match mwalib major and minor version, not patch version. This allows more flexibility in releases.
* No other changes.

* Requires mwalib 0.8.7.
* Updated API to match mwalib v0.8.7.
* Added helper function get_fine_chan_freqs_hz_array to correlator context and voltage context.
* Added metafits_context.num_metafits_fine_chan_freqs & metafits_context.metafits_fine_chan_freqs_hz, providing a list of sky frequencies for all fine channels.
* Added metafits_context.volt_fine_chan_width_hz & metafits_context.num_volt_fine_chans_per_coarse to describe the voltage fine channel configuration.

* Requires mwalib 0.8.4.
* Bumped version for new mwalib version compatibility.