feat: Lint .yamllint by default

docs/configuration.rst

@@ -126,6 +126,7 @@ configuration option. The default is:
  yaml-files:
  - '*.yaml'
  - '*.yml'
+ - '.yamllint'
 
 The same rules as for ignoring paths apply (``.gitignore``-style path pattern,
 see below).

tests/test_config.py

@@ -448,11 +448,13 @@ class IgnorePathConfigTestCase(unittest.TestCase):
         out = sys.stdout.getvalue()
         out = '\n'.join(sorted(out.splitlines()))
 
+        docstart = '[warning] missing document start "---" (document-start)'
         keydup = '[error] duplication of key "key" in mapping (key-duplicates)'
         trailing = '[error] trailing spaces (trailing-spaces)'
         hyphen = '[error] too many spaces after hyphen (hyphens)'
 
         self.assertEqual(out, '\n'.join((
+            './.yamllint:1:1: ' + docstart,
             './bin/file.lint-me-anyway.yaml:3:3: ' + keydup,
             './bin/file.lint-me-anyway.yaml:4:17: ' + trailing,
             './bin/file.lint-me-anyway.yaml:5:5: ' + hyphen,

yamllint/conf/default.yaml

@@ -3,6 +3,7 @@
 yaml-files:
   - '*.yaml'
   - '*.yml'
+  - '.yamllint'
 
 rules:
   braces: enable

yamllint/config.py

@@ -33,7 +33,7 @@ class YamlLintConfig(object):
         self.ignore = None
 
         self.yaml_files = pathspec.PathSpec.from_lines(
-            'gitwildmatch', ['*.yaml', '*.yml'])
+            'gitwildmatch', ['*.yaml', '*.yml', '.yamllint'])
 
         if file is not None:
             with open(file) as f: