fix PMD warnings

Author: eugene-matvejev

src/Container/FileContainer.php

@@ -12,7 +12,7 @@ class FileContainer
     const TYPE_UNKNOWN = 'unknown';
     const TYPE_SCSS    = 'scss';
     const TYPE_LESS    = 'less';
-    static $supportedTypes = [
+    public static $supportedTypes = [
         self::TYPE_SCSS,
         self::TYPE_LESS
     ];

src/Processor/Processor.php

@@ -22,7 +22,7 @@ class Processor
     const FORMATTER_EXPANDED   = 'expanded';
     const FORMATTER_NESTED     = 'nested';
     const FORMATTER_COMPACT    = 'compact';
-    static $supportedFormatters = [
+    public static $supportedFormatters = [
         self::FORMATTER_COMPRESSED,
         self::FORMATTER_CRUNCHED,
         self::FORMATTER_EXPANDED,