rb - fix bug for finding drivers on windows

(cherry picked from commit c0d2fca)

Author: titusfortner

rb/lib/selenium/webdriver/common/platform.rb

@@ -168,7 +168,9 @@ def find_binary(*binary_names)
 
         binary_names.each do |binary_name|
           paths.each do |path|
-            exe = Dir.glob(File.join(path, binary_name)).first
+            full_path = File.join(path, binary_name)
+            full_path.tr!('\\', '/') if windows?
+            exe = Dir.glob(full_path).first
             next unless exe
             return exe if File.executable?(exe)
           end