script.sh: update to match main repo

ci/travis/script.sh

@@ -10,7 +10,7 @@
 
 header 'Running script.sh...'
 
-modified_ruby_files=($(git diff --name-only --diff-filter=AM "${TRAVIS_COMMIT_RANGE}" -- *.rb))
+modified_ruby_files=($(git diff --name-only --diff-filter=AMR "${TRAVIS_COMMIT_RANGE}" -- *.rb))
 
 for file in "${modified_ruby_files[@]}"; do
   [[ "${file}" == 'Casks/'* ]] && modified_casks+=("${file}") || casks_wrong_dir+=("${file}")