CompatHelper: bump compat for MLJ to 0.18 for package classification,…

… (keep existing compat) (#134)

This pull request changes the compat entry for the `MLJ` package from `0.17` to `0.17, 0.18` for package classification.
This keeps the compat entries for earlier versions.



Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

examples/classification/Project.toml

@@ -14,7 +14,7 @@ CairoMakie = "0.7"
 CalibrationErrors = "0.6"
 DataFrames = "1"
 Distributions = "0.25"
-MLJ = "0.17"
+MLJ = "0.17, 0.18"
 MLJNaiveBayesInterface = "0.1.5"
 PalmerPenguins = "0.1.2"
 julia = "1.3"