firstErrorOf: couldn't parse failure report

Hey Aaron! Got this while hanging with you on Twitch:

```
Expected one of the following to exist:
- with text
> PLEASE REPORT THIS AT : firstErrorOf: couldn't parse failure report: Expecting Keyword tag at row 77, col 17
Expecting Keyword text at row 77, col 17
Expecting Keyword attribute at row 77, col 17
Expecting Keyword containing at row 77, col 17
Expecting ] at row 77, col 17
Expecting Keyword attribute at row 77, col 17
Expecting Keyword containing at row 77, col 17 Expecting ] at row 77, col 17
- with submit with value
> PLEASE REPORT THIS AT : firstErrorOf: couldn't parse failure report: Expecting Keyword tag at row 77, col 17
Expecting Keyword text at row 77, col 17
Expecting Keyword attribute at row 77, col 17
Expecting Keyword containing at row 77, col 17 Expecting ] at row 77, col 17
```

Here is the project at the commit producing the error:
https://github.com/ryannhg/elm-uno/tree/ca8c3719285df279998d47245dab5132ed68b077

You can run `npm run test` to reproduce this ( or `elm-test` )

Run `npm run test` or `elm-test` in the linked `elm-uno` project at the reported commit to reproduce the parser failure. Trace the `firstErrorOf` failure-report parsing entry point and compare the output at row 77, column 17 with the reported expectations. Done means the test suite no longer emits the parsing error for this reproduction.

Written by the indexing model from the issue text.