grammar: make resource record class (like `IN`) optional

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 1.1.1
+
+IMPROVEMENTS:
+
+- Make resource record class (like `IN`) optional
+
 ## 1.1.0 (November 26, 2017)
 
 NEW FEATURES:

grammars/zonefile.cson

@@ -29,7 +29,7 @@ repository:
             name: 'variable.other.entry.control.zonefile'
       }
       {
-        begin: '((@)|([A-Za-z0-9_.-]+))?(\\s+\\d+[A-Za-z])?\\s+(IN|in|CH|ch)\\s+(\\w+)\\s+'
+        begin: '((@)|([A-Za-z0-9_.-]+))?(\\s+\\d+[A-Za-z])?(\\s+IN|in|CH|ch)?\\s+(\\w+)\\s+'
         beginCaptures:
           '2':
             name: 'keyword.entry.resource.record.zonefile'