(TK-344) Explicitly specify all logback dependencies
(TK-344) Explicitly specify all logback dependencies

This commit adds explicit dependencies on all of the logback
artifacts that we use, to ensure that they are all the same version.
This also ensures that if any downstream projects happen to bring
in a conflicting version, the conflict will be caught at build time.

camlow325/trapperkeeper,puppetlabs/trapperkeeper