Add black step in tox.ini and Travis, as well as the badge

1 files changed, 6 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini
index 3e78f504..14881de1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -38,6 +38,12 @@ commands =
     ; inside the package
     python -Wi {envsitepackagesdir}/coverage run -m pytest --pyarg astroid/tests {posargs:}
 
+[testenv:formatting]
+basepython = python3
+deps = black==18.6b4
+commands = black --check --exclude "tests/testdata" astroid
+changedir = {toxinidir}
+
 [testenv:coveralls]
 setenv =
     COVERAGE_FILE = {toxinidir}/.coverage