I have download the caert.pem file and save it in C:\wamp\bin\php\php5.5.12, with the proper extension. Next I modified and uncomment the next line:
curl.cainfo = "c:/wamp/bin/php/php5.5.12/cacert.pem"
But it still doesn't work.
EDIT: We have to modify
C:\wamp\bin\apache\apache2.4.9\bin\ if we use wampserver (instead of