use 3.3.1 for user agent, not 3.3
use 3.3.1 for user agent, not 3.3

FTrubitz/twilio-php,beachboysapp/urgentMe,sayan801/twilio-php,achoe/twilio-php,Git-Host/twilio-php,javierwilson/twilio-php,beachboysapp/urgentMe,pablophg/twilio-php,twilio/twilio-php,MartinAmps/twilio-php