Xdoctest

There is nothing too special functionality-wise about this 1.0 release, except that xdoctest has been in a 1.0 state for a long time. It is now widely used, and it deserves to be marked as the mature and stable library that it is.

Added
* Support for Python 3.10

Fixed
* Warning in pytest8 (thanks amolenaar)
* Spelling errors in documentation

Changed

* The xdoctest "analysis" option now defaults to "auto" everywhere.

Fixed

* Fix issue 112 `--analysis=dynamic` argument is now respected

Changed

* Added GitHub actions to the CI
* Disabled workaround 16806 in Python 3.8+
* New CI GPG Keys: Erotemic-CI: 70858F4D01314BF21427676F3D568E6559A34380 for
reference the old signing key was 98007794ED130347559354B1109AC852D297D757.


Fixed

* Fixed minor test failures
* Fixed 106 - an issue to do with compiling multiline statements in single mode.
* Fixed 108 - an issue to do with compiling semicolon token in eval mode.

Changed
* Removed the distracting and very long internal traceback that occurred in
pytest when a module errors while it is being imported before the doctest is
run.
* Pytest now defaults to `--xdoctest-verbose=2` by default (note this does
nothing unless `-s` is also given so pytest does not supress output)

Yanked - contained debug print statements

Changed
* Directive syntax errors are now handled as doctest runtime errors and return better debugging information.
* README and docs were improved