Fixing date generation pattern in Phoenix-Pherf

pherf is generating date in two different patterns using two different API's , SimpleDateformat( pattern -> yyyy-MM-dd HH:mm:ss.SSS z with time zone ) and Joda Date format (pattern -> yyyy-MM-dd HH:mm:ss.SSS without time zone). We need to follow one pattern which have time zone in it using Joda Date Format.