v0.5.3

Upgrade instructions:

• Follow the upgrade instructions for any previous releases.
• Change Biff's :sha value in deps.edn and tasks/deps.edn to 92a03324f98836d579878fc669eb702746551858.

Added:

• Added :db.op/upsert and :db/unique operations to Biff transactions. db.op/upsert is like :db/lookup, but implemented with a transaction function. See the transaction docs. In addition, biff/submit-tx has been refactored further to make it easier to extend. This isn't yet documented, but see the :biff.xtdb/transformers option.

Fixed:

• Changed Execstart to ExecStart in setup.sh.
• Continue running :on-tx functions even if one of them fails.