(MAINT) Generalize .gitattributes
(MAINT) Generalize .gitattributes

So it's easier to maintain by not listing out all the subdirectories
underneath docker/.

puppetlabs/puppet-server,puppetlabs/puppetserver,puppetlabs/puppet-server,puppetlabs/puppet-server,puppetlabs/puppetserver,puppetlabs/puppetserver,puppetlabs/puppetserver