Updated files with 'repo_helper'. (#37)

Co-authored-by: repo-helper[bot] <74742576+repo-helper[bot]@users.noreply.github.com>

Author: repo-helper[bot]

tox.ini

@@ -15,10 +15,11 @@
 [tox]
 envlist = py36, py37, py38, py39, py310-dev, pypy3, mypy, build
 skip_missing_interpreters = True
+isolated_build = True
 requires =
     pip>=20.3.3
     tox-envlist>=0.1.0
-isolated_build = True
+    tox-pip-version==0.0.7
 
 [envlists]
 test = py36, py37, py38, py39, py310-dev, pypy3
@@ -28,11 +29,10 @@ cov = py36, coverage
 [testenv:docs]
 setenv = SHOW_TODOS = 1
 basepython = python3.8
+pip_version = pip>=21
 changedir = {toxinidir}/doc-source
 extras = all
-deps =
-    -r{toxinidir}/requirements.txt
-    -r{toxinidir}/doc-source/requirements.txt
+deps = -r{toxinidir}/doc-source/requirements.txt
 commands = sphinx-build -M html . ./build {posargs}
 
 [testenv:build]