Fix linux plan to use ruby 2.7
Fix linux plan to use ruby 2.7

Signed-off-by: John Snow <47c542fb4e3a457d9f319341436ccc3fdc5cc6bc@outlook.com>

MsysTechnologiesllc/chef,jaymzh/chef,jaymzh/chef,MsysTechnologiesllc/chef,nvwls/chef,chef/chef,mwrock/chef,mwrock/chef,mattray/chef,higanworks/chef,MsysTechnologiesllc/chef,MsysTechnologiesllc/chef,chef/chef,nvwls/chef,chef/chef,mattray/chef,tas50/chef-1,higanworks/chef,higanworks/chef,tas50/chef-1,mwrock/chef,tas50/chef-1,higanworks/chef,mattray/chef,gene1wood/chef,tas50/chef-1,higanworks/chef,nvwls/chef,mwrock/chef,gene1wood/chef,chef/chef,nvwls/chef,jaymzh/chef,gene1wood/chef,nvwls/chef,mattray/chef,gene1wood/chef,mattray/chef,jaymzh/chef,nvwls/chef