Changelog for QCoDeS 0.16.0

The July 2020 release of QCoDeS.

Note: this will be the last QCoDeS release to support python 3.6

Breaking Changes:

math has been renamed to math_utils (2040).
The deprecated default_measurement of the Station is now removed (2058)
The deprecated methods get_data and get_values of the DataSet have now been removed (2067)
The get_setpoints method of the DataSet has been deprecated (2068)

The Keithley 2450 driver got a bunch of new parameters and methods (1970, 2052)
The Keysight B1500 driver now checks errors after setting each parameter (2041) and outputs NaN instead of 199.999e99 when compliance is reached (2074)
The Keysight B1520A driver saw a bunch of improvements:
- sweep API was restructured more logically (2044)
- the driver now supports all possible impedance models (2047)
- the measurement status is retrieved after each sweep (2050)
- added get_cmds for sweep_auto_abort and post_sweep_auto_abort (2049)
The Keysight B1517A driver had the following improvements:
- the measurement status is retrieved after each sweep (2050).
- added get_cmds for sweep_auto_abort and post_sweep_auto_abort (2049)
- added measurement status to current/voltage parameters (2051)

All master-slave references from drivers have been removed or deprecated (2066)
QCoDeS now comes with a code of conduct (2078)

Better execution of the test suite and hardening of tests (2016, 2037, 2038, 2039, 2040, 2042, 2045, 2056, 2057, 2063, 2064, 2070, 2073, 2077, 2076). Special highlights from this massive work:
- The test suite now runs in parallel, a major win for all developers
- Much better handling of the QCoDeS config system as a result
Update of dependencies to mypy 0.782 (2034, 2075) and pyqtgraph 0.11.0 (2036)
The measurements.py module is now slightly better type-annotated (2065)
Documentation is built with Spinx 3.1.2 (2069, 2072)
Added support for (upcoming) pytest 6 and explicit dependency on packaging (2076)