Avoid use of srand/rand in unittest/random.h
Avoid use of srand/rand in unittest/random.h

Fixes issue 129

lishi0927/thrust,hemmingway/thrust,malenie/thrust,allendaicool/thrust,h1arshad/thrust,hemmingway/thrust,rdmenezes/thrust,rdmenezes/thrust,allendaicool/thrust,levendlee/thrust,UIKit0/thrust,UIKit0/thrust,google-code-export/thrust,UIKit0/thrust,hemmingway/thrust,malenie/thrust,malenie/thrust,Vishwa07/thrust,allendaicool/thrust,Vishwa07/thrust,Vishwa07/thrust,h1arshad/thrust,levendlee/thrust,julianromera/thrust,levendlee/thrust,hemmingway/thrust,google-code-export/thrust,malenie/thrust,lishi0927/thrust,h1arshad/thrust,julianromera/thrust,julianromera/thrust,google-code-export/thrust,bfurtaw/thrust,bfurtaw/thrust,rdmenezes/thrust,lishi0927/thrust,julianromera/thrust,Vishwa07/thrust,bfurtaw/thrust,allendaicool/thrust,rdmenezes/thrust,UIKit0/thrust,google-code-export/thrust,lishi0927/thrust,levendlee/thrust,bfurtaw/thrust,h1arshad/thrust