Generated mocks are outdated

[thijmv]

The generated mocks under /mocks are outdated, i.e. running make mocks would introduce changes to the mocks.

[aman-coder03]

hi @thijmv i looked into this issue and wanted to check, is this still reproducible on the current master?
several recent commits(#548, #545) updated mocks directly
i would like to take this on but wanted to confirm the issue is still open before regenerating. Happy to run make mocks and submit a PR if needed

[thijmv]

If you run make mocks using the latest version of mockgen, it introduces some changes. On this note, I would also suggest updating the Makefile target to include stdlib mocks. Currently, we have no way to regenerate them, despite using them (eg. mocks/io). Does that make sense? @aman-coder03

[aman-coder03]

thanks @thijmv! I'll update the Makefile to add the mocks/io target and switch to the latest mockgen (go.uber.org/mock)