add change log for version 0.1 -> 0.5
add change log for version 0.1 -> 0.5

aitboudad/Payum,digisec/Payum,ASKozienko/Payum,StoreFactory/Payum,formapro-forks/Payum,fullpipe/Payum,formapro-forks/Payum,StoreFactory/Payum,staabm/Payum,Payum/Payum,StoreFactory/Payum,fullpipe/Payum,digisec/Payum,Payum/Payum