Bump train-core to 3.4.8
Bump train-core to 3.4.8

This pull request was triggered automatically via Expeditor when train-core 3.4.8 was promoted to Rubygems.

This change falls under the obvious fix policy so no Developer Certificate of Origin (DCO) sign-off is required.

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