Remove outdated/unnecessary todo

go/fake-http/README.md

## TODO
- replay from log instantly (i.e. operate like a request cache)
    - ensure every request is cached max once?  at least in the response
      defn?
    - make it possible to download the cache
        - /_cache, analogous to /_log?
        - or reuse /_log, which wouldn't need new code, but would make
          it impossible to download the log.  damn...
            - how about /_log?cache=true?
            - or make /_log redirect to /_cache if `-cache` is enabled
- /_clear endpoint
- some kind of templating (request info + random functions?)
- lua integration? ;)