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)