next.jdbc.specs

Specs for the core API of next.jdbc. The functions from `next.jdbc`, `next.jdbc.sql`, and `next.jdbc.prepare` have specs here. Just `:args` are spec'd. These specs are intended to aid development with `next.jdbc` by catching simple errors in calling the library. The `connectable` argument is currently just `any?` but both `get-datasource` and `get-connection` have stricter specs. In addition, there is an `instrument` function that provides a simple way to instrument all of the `next.jdbc` functions, and `unstrument` to undo that.