I believe that there is no reason not to remove sudo and use jobs in place of matrix. Not specifying os and dist allows automatic update in case Travis changes the defaults. cabal warning is false positive according to https://docs.travis-ci.com/user/languages/haskell/ .
Linter issues:
I believe that there is no reason not to remove
sudoand usejobsin place ofmatrix. Not specifyingosanddistallows automatic update in case Travis changes the defaults.cabalwarning is false positive according to https://docs.travis-ci.com/user/languages/haskell/ .