[maint] Fix development group naming in .sync.yml
[maint] Fix development group naming in .sync.yml

This current .sync.yml produces an invalid Gemfile. development group is specified in the Gemfile with a symbol and as such needs to be prefixed with a colon.

jpogran/puppetlabs-iis,puppetlabs/puppetlabs-iis,puppetlabs/puppetlabs-iis,jpogran/puppetlabs-iis