when updating hspec to 2.9.0, must change configFastFail to configFailFast

My **test wasn't compiling** (which has not be modified at all, fresh from download), and cabal reported this error:
```
test\Tests.hs:9:27: error:
Module `Test.Hspec.Runner' does not export `configFastFail'
9 | import Test.Hspec.Runner (configFastFail, defaultConfig, hspecWith)
| ^^^^^^^^^^^^^^
```
Searching online I found the `hspec` [changelog](https://hackage.haskell.org/package/hspec-2.9.4/changelog) (the latest version).
It reports that in version "2.9.0":
```
Changes in 2.9.0
- Add ASCII fallbacks to "checks" formatter (fixes #512)
- Use checks formatter by default (to restore the old behavior use --format specdoc)
- Allow to extend the list of available formatters for --format (configAvailableFormatters)
- Add getExpectedTotalCount to Test.Hspec.Core.Formatters.V2
- Rename formatConfigItemCount to formatConfigExpectedTotalCount
- Rename configFastFail to configFailFast <--!!!!
```
The important line: "Rename configFastFail to **configFailFast**"
By updating the import, everything compiled just fine.

I'm not making a pr because, no one else seems to have reported it, so I'm not sure I've messed up something or is a real "bug".
If I haven't messed up, then the only corrections to be applied are:
- `import Test.Hspec.Runner (configFailFast, defaultConfig, hspecWith)` on line 9
- `main = hspecWith defaultConfig {configFailFast = True} specs` on line 14