Use path overrides for the full workspace
Use path overrides for the full workspace

By adding the `[replace]` here, the override acts more like the path
overrides in `.cargo/config` used to. This ensures that all member
crates are using the local version when running tests. I'm not sure
if/how this is used when publishing to crates.io, but presumably it'll
error if it's not ignored. I guess I'll find out when we release later
this week.

diesel-rs/diesel,sgrif/diesel,diesel-rs/diesel,sgrif/diesel