Update addons-linter to 0.18.1 (#5152)

* Update addons-linter to 0.18.1

* Fix test (different, new rules, slightly different results)

package.json

@@ -7,7 +7,7 @@
     "npm": ">= 1.1.x"
   },
   "dependencies": {
-    "addons-linter": "0.17.0",
+    "addons-linter": "0.18.1",
     "clean-css": "4.0.11",
     "clean-css-cli": "4.0.10",
     "less": "2.7.2",

src/olympia/devhub/tests/test_tasks.py

@@ -438,7 +438,7 @@ class TestRunAddonsLinter(ValidatorTestCase):
 
             assert tmpf.call_count == 2
             assert result['success']
-            assert result['warnings'] == 24
+            assert result['warnings'] == 22
             assert not result['errors']