run php tests on 5.5 as well
run php tests on 5.5 as well

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