Add test requirements to Pipfile[.lock] & bump deps (#2436)

While this development environment / requirements situation is a mess,
let's at least make it consistent. We're effectively supporting two
modes of development in this project, 1) tox based dev commands
(e.g. `tox -e fuzz`) that are dead simple to use, and 2) manual dev
commands (e.g. `pytest -n auto`) that give more control and are usually
faster.

Right now the Pipfile.lock based development environment is incomplete
missing the test requirements specified in ./test_requirements.txt.
This is annoying since manual test commands (e.g. `pytest -k fmtonoff`)
fail. Let's fix this by making Pipfile.lock basically a
"everything you need" requirements file (fuzzing not included since
running it locally is not something common).

Oh and let's bump some documentation deps (and bring some requirements
across .pre-commit-config.yaml, Pipfile, and docs/requirement.txt in
alignment again). Don't worry, I tested these changes so they should
be fine (hopefully!).

.pre-commit-config.yaml

@@ -19,7 +19,7 @@ repos:
         additional_dependencies: [flake8-bugbear]
 
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.902
+    rev: v0.910
     hooks:
       - id: mypy
         exclude: ^docs/conf.py
@@ -31,7 +31,7 @@ repos:
           - platformdirs >= 2.1.0
 
   - repo: https://github.com/pre-commit/mirrors-prettier
-    rev: v2.3.1
+    rev: v2.3.2
     hooks:
       - id: prettier
         exclude: ^Pipfile\.lock

Pipfile

@@ -4,23 +4,38 @@ url = "https://pypi.python.org/simple"
 verify_ssl = true
 
 [dev-packages]
-Sphinx = ">=3.1.2"
-coverage = "*"
-docutils = "==0.15"  # not a direct dependency, see https://github.com/pypa/pipenv/issues/3865
-flake8 = "*"
+# Testing related requirements.
+coverage = ">= 5.3"
+pytest = " >= 6.1.1"
+pytest-mock = ">= 3.3.1"
+pytest-cases = ">= 2.3.0"
+pytest-xdist = ">= 2.2.1"
+pytest-cov = ">= 2.11.1"
+parameterized = ">= 0.7.4"
+tox = "*"
+
+# Linting related requirements.
+pre-commit = ">=2.9.2"
+flake8 = ">=3.9.2"
 flake8-bugbear = "*"
-mypy = ">=0.812"
+mypy = ">=0.910"
 types-dataclasses = ">=0.1.3"
 types-typed-ast = ">=1.4.1"
-pre-commit = "*"
-readme_renderer = "*"
-MyST-Parser = ">=0.13.7"
+
+# Documentation related requirements.
+Sphinx = ">=4.1.2"
+MyST-Parser = ">=0.15.1"
 sphinxcontrib-programoutput = ">=0.17"
-sphinx-copybutton = ">=0.3.0"
+sphinx-copybutton = ">=0.4.0"
+docutils = "==0.17.1"  # not a direct dependency, see https://github.com/pypa/pipenv/issues/3865
+
+# Packaging related requirements.
 setuptools = ">=39.2.0"
 setuptools-scm = "*"
 twine = ">=1.11.0"
 wheel = ">=0.31.1"
+readme_renderer = "*"
+
 black = {editable = true, extras = ["d", "jupyter"], path = "."}
 
 [packages]