Revert "msgpack incompatible with Go 1, try to use json instead."
Revert "msgpack incompatible with Go 1, try to use json instead."

This reverts commit 807bcc77f9fe84685d16a8af112e099103bf7605.

vincentbernat/aptly,neolynx/aptly,gdbdzgd/aptly,bsundsrud/aptly,ceocoder/aptly,vincentbernat/aptly,smira/aptly,vincentbernat/aptly,adfinis-forks/aptly,adfinis-forks/aptly,gdbdzgd/aptly,jola5/aptly,sobczyk/aptly,adfinis-forks/aptly,smira/aptly,scalp42/aptly,scalp42/aptly,sobczyk/aptly,seaninspace/aptly,ceocoder/aptly,gdbdzgd/aptly,gearmover/aptly,aptly-dev/aptly,gearmover/aptly,seaninspace/aptly,bankonme/aptly,bsundsrud/aptly,sobczyk/aptly,ceocoder/aptly,bankonme/aptly,scalp42/aptly,jola5/aptly,jola5/aptly,seaninspace/aptly,gearmover/aptly,bankonme/aptly,aptly-dev/aptly,aptly-dev/aptly,smira/aptly,neolynx/aptly,neolynx/aptly,bsundsrud/aptly