modify selenium version

README.md

@@ -7,7 +7,7 @@ Find the latest version on github : https://github.com/amazingTest/violent_webdr
 The last stable release is available on PyPI and can be installed with pip.
 make sure that Chrome has been installed and match the selenium version
 
-    $ pip install selenium==3.11.0    
+    $ pip install selenium
     $ pip install violent_webdriver
     
 ## Best Practice