Enables pylint W1503

The testIdentity changed here was using assertTrue with a constant
instead of a conditional. So, to make lint pass it was updated to a more
appropriate assert.
Signed-off-by: NCaio Carrara <ccarrara@redhat.com>

examples/tests/multiple_tests.py

@@ -18,7 +18,7 @@ class MultipleTests(Test):
         self.assertEqual(self.hello, "Hi there!")
 
     def testIdentity(self):
-        self.assertTrue(1, 1)
+        self.assertIs(1, 1)
 
     def division_by_zero(self):
         """

selftests/checkall

@@ -169,7 +169,7 @@ results_dir_content() {
 [ "$SKIP_RESULTSDIR_CHECK" ] || RESULTS_DIR_CONTENT="$(ls $RESULTS_DIR 2> /dev/null)"
 
 LINT_CMD="inspekt lint --exclude=.git"
-PYLINT_ENABLE="--enable R0401,W0101,W0102,W0104,W0105,W0106,W0107,W0108,W0109,W0111,W0120,W0122,W0123,W0124,W0125,W0150,W0199,W0211,W0222,W0232,W0233,W0301,W0312,W0401,W0404,W0406,W0410,W0601,W0602,W0603,W0604,W0611,W0612,W0614,W0622,W0623,W0640,W0711,W1202,W1300,W1301,W1302,W1303,W1304,W1305,W1306,W1307,W1401,W1402,W1501,W1645"
+PYLINT_ENABLE="--enable R0401,W0101,W0102,W0104,W0105,W0106,W0107,W0108,W0109,W0111,W0120,W0122,W0123,W0124,W0125,W0150,W0199,W0211,W0222,W0232,W0233,W0301,W0312,W0401,W0404,W0406,W0410,W0601,W0602,W0603,W0604,W0611,W0612,W0614,W0622,W0623,W0640,W0711,W1202,W1300,W1301,W1302,W1303,W1304,W1305,W1306,W1307,W1401,W1402,W1501,W1503,W1645"
 if [ "$AVOCADO_PARALLEL_LINT" ]; then
     LINT_CMD="$LINT_CMD --parallel=$AVOCADO_PARALLEL_LINT"
 fi