Alchemtest

Release with new AMBER tests files (with intentional errors to test error handling).

What's Changed
* added tests for the new regex by DrDomenicoMarson in https://github.com/alchemistry/alchemtest/pull/86


**Full Changelog**: https://github.com/alchemistry/alchemtest/compare/0.7.1...0.8.0

Bug fix release

* corrected one of the AMBER test files for incorrect data (PR 84 )

Changes
* follow [NEP 29](https://numpy.org/neps/nep-0029-deprecation_policy.html) and removed support for Python 2.x and Python ≤3.6: Support **Python ≥ 3.7** (tested up to 3.11) (see #77)

New data files
* additional AMBER data files with incomplete or partially corrupted content to test failure (available in [`alchemtest.amber.load_testfiles()`](https://alchemtest.readthedocs.io/en/latest/amber.html#alchemtest.amber.load_testfiles)) (69).

Deprecations
* [`alchemtest.amber.load_invalidfiles()`](https://alchemtest.readthedocs.io/en/latest/amber.html#alchemtest.amber.load_invalidfiles) is deprecated and will be removed. Use `alchemtest.amber.load_testfiles()` instead (65).

Changes
* new AMBER test files for invalid inputs
* reorganized AMBER test files

This is release candidate 1 (to test automatic deployment).

Release with new datasets and official support for Python 3.10.

(Note that Python 2.7 and 3.5-3.7 remain supported because it is not difficult to do so, but as soon as any problems arise, we will drop older versions in line with [NEP 29](https://numpy.org/neps/nep-0029-deprecation_policy.html).)

New datasets and almost fully tested.

This release still supports legacy versions of Python (2.7, 3.5, 3.6) but future versions of alchemtest will not actively pursue supporting legacy versions and adopt NEP 29 (in line with alchemlyb, see [alchemistry/alchemlyb140](https://github.com/alchemistry/alchemlyb/issues/140)).