Add snappy to a somewhat silly comment.

Author: benson-basis

src/main/java/org/codehaus/plexus/archiver/tar/TarUnArchiver.java

@@ -58,9 +58,10 @@ public TarUnArchiver( File sourceFile )
      * <p/>
      * Allowable values are
      * <ul>
-     * <li>none - no compression
-     * <li>gzip - Gzip compression
-     * <li>bzip2 - Bzip2 compression
+     * <li>none - no compression</li>
+     * <li>gzip - Gzip compression</li>
+     * <li>bzip2 - Bzip2 compression</li>
+     * <li>snappy - Snappy compression</li>
      * </ul>
      *
      * @param method compression method