Web tweaks, preparing to open source

- Switched to placeholder Firebase name to match readme
- Fixed a couple nits on web
- Added a log message on web when auth fails, since there are lots of ways auth could get configured wrong

@alexwolfe or @joeyyang: Would either of you mind giving the tiny web changes a quick review?  k thx :)
This is fine for an example I guess but generally I like to remove all console.logs from production code in case the browser doesn't have this method.