enhancement: make possible to run tests and related stuff using tox

Make possible to run tests (python setup.py test) and other related
stuff (flake8, doc8 and yamllint) using tox.

Signed-off-by: Satoru SATOH <satoru.satoh@gmail.com>

requirements.txt

@@ -0,0 +1,3 @@
+pathspec >= 0.5.3
+pyyaml
+setuptools

tests/requirements.txt

@@ -0,0 +1,6 @@
+pyyaml
+coveralls
+flake8
+flake8-import-order
+doc8
+sphinx; python_version > '2.7'

tox.ini

@@ -0,0 +1,30 @@
+[tox]
+envlist = py27, py34, py35, py36, py37, py38, nightly
+minversion = 3.15
+
+[base]
+commands =
+    - /bin/sh -c 'yamllint -c {toxinidir}/yamllint/conf/default.yaml --strict `git ls-files \*.yaml \*.yml`'
+    coverage run --source=yamllint setup.py test
+
+[testenv]
+deps =
+    -r {toxinidir}/requirements.txt
+    -r {toxinidir}/tests/requirements.txt
+
+# https://tox.readthedocs.io/en/latest/config.html#substitution-for-values-from-other-sections
+commands =
+    /bin/sh -c 'doc8 `git ls-files \*.rst`'
+    {[base]commands}
+    python setup.py build_sphinx
+
+[testenv:py27]
+commands =
+    flake8 .
+    {[base]commands}
+
+# https://tox.readthedocs.io/en/latest/config.html#generative-section-names
+[testenv:py3{4,5,6,7,8}]
+commands =
+    flake8 .
+    {[testenv]commands}