Added IPv4#to_s benchmark test
Added IPv4#to_s benchmark test

mabels/ipaddress,ipaddress-gem/ipaddress,mabels/ipaddress,paudam/ipaddress,mabels/ipaddress,mabels/ipaddress,gferguson-gd/ipaddress,ghg/ipaddress,mabels/ipaddress,mabels/ipaddress,bluemonk/ipaddress,mabels/ipaddress,mabels/ipaddress,mabels/ipaddress,mabels/ipaddress