Updates Rakefile from obsolete rake/rdoctask to rdoc/task
Updates Rakefile from obsolete rake/rdoctask to rdoc/task

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