Attributes containing `"` lead to a failure to show error details

When:
- the view html contains attributes like `Html.Attributes.attribute "contains-double-quote" "\""`
- and a selector does not match, then

elm-program-test shows an error like:

```
PLEASE REPORT THIS AT : renderHtml: couldn't parse failure report: Unexpected Char at row 4, col 10

▼ ProgramTest.clickButton "that does not exist"

Expected one of the following to exist:
- with text
✓ has tag "button"
✗ has containing [ text "that does not exist" ]
- with with alt text
...etc etc...
```

Here's a commit demonstrating that in the test cases: https://github.com/avh4/elm-program-test/commit/b67267b92110420b918acdfd20742ba7d5cdbf74

Reproduce the failure from commit b67267b92110420b918acdfd20742ba7d5cdbf74 using an attribute containing a double quote and ProgramTest.clickButton. Start at the renderHtml failure-report parsing path; done means the selector mismatch report renders its error details instead of failing with an Unexpected Char message.

Written by the indexing model from the issue text.