Pin pylint to 2.10.2 in osm charms

Change-Id: I238d04075c56ed6544df6d91eef16fc1a6b545c4
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/lcm/tox.ini b/installers/charm/lcm/tox.ini
index c341c8e..8e3318a 100644
--- a/installers/charm/lcm/tox.ini
+++ b/installers/charm/lcm/tox.ini
@@ -69,7 +69,7 @@
 [testenv:pylint]
 deps =  {[testenv]deps}
         -r{toxinidir}/requirements-test.txt
-        pylint
+        pylint==2.10.2
 commands =
     pylint -E src/ tests/