setup.py: update dependencies and metadata

* Add python_requires metadata. The latest pyroma does check for its
  presence and it makes sense to add it to prevent from installing
  the package on the wrong Python version.
* Revert old upper limit for GitPython, there are no more issue with
  more recent versions.
* Set an upper limit for pylint and prospector. A change in pylint broke
  prospector, but we can't upgrade prospector because of an upstream
  bug, see:
  landscapeio/prospector#545
* Split the python auto-formatter test dependencies on their own extra
  group so that they can be installed alone in the already split virtual
  environment for the tox envs py3-style and py3-format.
  This way there are no conflicts between other test dependencies and
  black and isort.
* Add specific style tox environments for each Python version to avoid
  the CI jobs to pick Python 3.7 that has a pip backtracking issue with
  the latest versions of the dependencies. Keep the py3-{style,format}
  environments for ease of use locally and to not break compatibility
  but make the py3-style one not run automatically in CI.

Change-Id: I6ce05223df3bf17e269994ee7501ec16e35c76dd

setup.py

@@ -12,8 +12,7 @@
     "dnspython>=1.16.0,<2.2.0",  # Temporary upper limit to prevent mypy failures
     "elasticsearch>=5.0.0,<7.15.0",
     "elasticsearch-curator>=5.0.0",
-    # TODO: gitpython 3.1.15 causes issues with mypy
-    "gitpython<=3.1.14",
+    "gitpython>=3.1.14",
     "kafka-python>=1.4.3",
     "kubernetes==12.0.*",  # frozen to the version available on debian bullseye
     "pymysql>=0.9.3",
@@ -28,9 +27,7 @@
     # Test dependencies
     "tests": [
         "bandit>=1.5.1",
-        "black<=21.12b0",  # this is needed so that it doesn't confict with curator
         "flake8>=3.6.0",
-        "isort",
         "mypy>=0.670",
         "pytest-cov>=2.6.0",
         "pytest-xdist>=1.26.1",
@@ -48,8 +45,13 @@
         "types-requests",
         "types-setuptools",
     ],
+    "format": [
+        "black<=21.12b0",  # this is needed so that it doesn't confict with curator
+        "isort",
+    ],
     "prospector": [
-        "prospector[with_everything]>=0.12.4",
+        "prospector[with_everything]>=0.12.4,<=1.7.7",  # Temporary upper limit for an upstream regression
+        "pylint<2.15.7",  # Temporary upper limit for a change that breaks prospector that can't be upgraded
         "pytest>=3.10.1",
         "requests-mock>=1.5.2",
     ],
@@ -91,6 +93,7 @@
     package_data={"spicerack": ["py.typed"]},
     packages=find_packages(exclude=["*.tests", "*.tests.*"]),
     platforms=["GNU/Linux"],
+    python_requires=">=3.9",
     setup_requires=SETUP_REQUIRES,
     use_scm_version=True,
     url="https://github.com/wikimedia/operations-software-spicerack",

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.10.0
-envlist = py{39,310}-{flake8,unit,bandit,mypy,prospector,sphinx},py3-style
+envlist = py{39,310}-{flake8,unit,bandit,mypy,prospector,sphinx},py{39,310}-style
 skip_missing_interpreters = True
 
 
@@ -22,9 +22,10 @@ description =
     py310: (Python 3.10)
 envdir =
     prospector: {toxworkdir}/{envname}
+    !py3-style: {toxworkdir}/{envname}
     py3: {toxworkdir}/py3-tests
-    py39-!prospector: {toxworkdir}/py39-tests
-    py310-!prospector: {toxworkdir}/py310-tests
+    py39-!prospector-!style: {toxworkdir}/py39-tests
+    py310-!prospector-!style: {toxworkdir}/py310-tests
 commands =
     flake8: flake8 setup.py spicerack
     style: {toxinidir}/utils/check-style.sh
@@ -45,7 +46,9 @@ commands =
     sphinx: sed -i='' -e 's/^\.B/.B /' '{toxinidir}/doc/build/man/cookbook.1'
 deps =
     # Use install_requires and the additional extras_require[tests/prospector] from setup.py
+    style: .[format]
+    format: .[format]
     prospector: .[prospector]
-    !prospector: .[tests]
+    !prospector-!style-!format: .[tests]
 
-[testenv:py3-format]
+[testenv:py3-{format,style}]