See the comment in tools.go, I cannot fully explain what's happening here.
Somehow, Go 1.14 wants to use the vendored version of oapi-codegen but
without this file, oapi-codegen isn't vendored so the generation fails.
Signed-off-by: Ondřej Budai <ondrej@budai.cz>
Write an openapi spec for the worker API and use `deepmap/oapi-codegen`
to generate scaffolding for the server-side using the `labstack/echo`
server.
Incidentally, echo by default returns the errors in the same format that
worker API always has:
{ "message": "..." }
The API itself is unchanged to make this change easier to understand. It
will be changed to better suit our needs in future commits.
