Merge pull request #5 from sbtqa/fix_set_driver_executable_for_linux

fix driver is executable now

src/main/java/io/github/bonigarcia/wdm/Downloader.java

@@ -107,6 +107,7 @@ private File download(URL url, File targetFile, String export)
         } else if (targetFile.getName().toLowerCase().endsWith(".msi")) {
             return extractMsi(targetFile);
         } else {
+            setFileExecutable(targetFile);
             return targetFile;
         }
     }