Add Ruby 2.5 testing to Travis
Add Ruby 2.5 testing to Travis

Signed-off-by: Tim Smith <764ef62106582a09ed09dfa0b6bff7c05fd7d1e4@chef.io>

nvwls/chef,Tensibai/chef,juliandunn/chef,higanworks/chef,jaymzh/chef,MsysTechnologiesllc/chef,nathwill/chef,mattray/chef,jaymzh/chef,gene1wood/chef,juliandunn/chef,gene1wood/chef,tas50/chef-1,jonlives/chef,Ppjet6/chef,jaymzh/chef,martinisoft/chef,mattray/chef,higanworks/chef,nathwill/chef,mattray/chef,mattray/chef,mwrock/chef,tomdoherty/chef,nathwill/chef,jonlives/chef,tomdoherty/chef,chef/chef,tomdoherty/chef,juliandunn/chef,chef/chef,jonlives/chef,tas50/chef-1,higanworks/chef,jaymzh/chef,MsysTechnologiesllc/chef,nvwls/chef,nathwill/chef,nathwill/chef,higanworks/chef,nvwls/chef,tas50/chef-1,Tensibai/chef,tomdoherty/chef,martinisoft/chef,jonlives/chef,juliandunn/chef,Ppjet6/chef,Tensibai/chef,nvwls/chef,MsysTechnologiesllc/chef,Tensibai/chef,mwrock/chef,jonlives/chef,nvwls/chef,juliandunn/chef,martinisoft/chef,Ppjet6/chef,mattray/chef,nathwill/chef,martinisoft/chef,Ppjet6/chef,martinisoft/chef,chef/chef,MsysTechnologiesllc/chef,tomdoherty/chef,tas50/chef-1,nvwls/chef,chef/chef,Tensibai/chef,Ppjet6/chef,gene1wood/chef,jonlives/chef,mwrock/chef,mwrock/chef,higanworks/chef,Ppjet6/chef,gene1wood/chef