Pymwalib

* Requires mwalib 0.8.3.
* Major refactoring of classes to be more consisten with mwalib, please see mwalib release notes for changes in the base library.
* `CorrelatorContext` and `VoltageContext` classes now have a metafits_context attribute containing the metafits attributes.
* Thus lists such as `rf_inputs`, `baselines`, `antennas` are now accessed via the metafits_context.
* MetafitsContext now has `metafits_timesteps` and `metafits_coarse_chans` which reflect those provided by the metafits file.
* In order to assist users make sense of the data files provided, CorrelatorContext and VoltageContext have `common`, `common_good` and `provided` lists of indices. See [mwalib wiki: Key Concepts](https://github.com/MWATelescope/mwalib/wiki/Key-Concepts) for an explanation of these terms.

* Requires mwalib 0.8.2.
* mwalib version is now checked upon creating an instance of MetafitsContext, CorrelatorContext or VoltageContext
* pymwalib.version.check_mwalib_version() is exposed so callers can check and handle version incompatibility before using a context object.
* Antenna now includes electrical length and north,east,height attributes
* MetafitsContext now has metafits_timesteps and metafits_coarse channels based on the metafits file only
* CorrelatorContext and VoltageContext now have timesteps and coarse channels based on a superset of data files provided and the metafits file
* CorrelatorContext and VoltageContext now have 'common' and 'common good' attributes describing the data files provided. 'Common' refers to timesteps and coarse channels which are common to all data files provided 'Common Good' determines 'Common' based on times after the quacktime.
* In CorrelatorContext read_by_baseline() and read_by_frequency(), the timestep index and coarse channel index are based on the indices of the CorrelatorContext.timesteps and coarse_channels lists
* In VoltageContext read_file() and read_second(), the timestep index and coarse channel index are based on the indices of the VoltageContext.timesteps and coarse_channels lists
* For all read methods If no data exists for a timestep index or coarse channel index, then a `PymwalibNoDataForTimestepAndCoarseChannel` exception is raised

* Requires mwalib 0.7.*.
* Added read methods for VoltageContext (to match 0.7.* of mwalib)
* Updated voltage context to match latest 0.7.* mwalib (removed num_samples_per_timestep and added many new descriptive attributes)
* Added paramter type hints to the correlator context read methods
* Added more tests for correlator context
* Updated CI to pip install numpy as some tests now require numpy

* Requires mwalib 0.6.*.
* Moved coax_v_factor, mwa_lat_radians, mwa_long_radians and mwa_alt_meters out of metafits_metadata and are now constants.

* Requires mwalib 0.5.1.
* Major refactor to match major refactor in mwalib 0.5.0. This will break compatibility with previous pymwalib versions.
* Context top level object now split into:
* MetafitsContext (when you only provide a metafits file)
* CorrelatorContext (when you provide a metafits and 1 or more gpubox files)
* VoltageContext (when you provide a metafits and 1 or more voltage files)
* Many new class members added to various classes.

* Requires mwalib 0.4.4.
* Added receiver_number and receiver_slot_number to rfinput struct.