Merge pull request #3234 from hsanson/3233-enable-ktlint-fixer-for-kotlin-files

Enable ktlint fixer for kotlin files.

autoload/ale/fix/registry.vim

@@ -342,7 +342,7 @@ let s:default_registry = {
 \   },
 \   'ktlint': {
 \       'function': 'ale#fixers#ktlint#Fix',
-\       'suggested_filetypes': ['kt'],
+\       'suggested_filetypes': ['kt', 'kotlin'],
 \       'description': 'Fix Kotlin files with ktlint.',
 \   },
 \   'styler': {