pin pylint deps in tox

Author: mufaddal-rohawala

tox.ini

@@ -88,7 +88,7 @@ commands = flake8
 skipdist = true
 skip_install = true
 deps =
-    pylint
+    pylint==2.6.2
     astroid==2.4.2
 commands =
     python -m pylint --rcfile=.pylintrc -j 0 src/sagemaker