Add alpine to generate-stackbrew-library.sh also

Author: ncopa

generate-stackbrew-library.sh

@@ -30,7 +30,7 @@ for version in "${versions[@]}"; do
 		echo "$va: ${url}@${commit} $version"
 	done
 
-	for variant in onbuild slim; do
+	for variant in onbuild slim alpine; do
 		commit="$(cd "$version/$variant" && git log -1 --format='format:%H' -- Dockerfile $(awk 'toupper($1) == "COPY" { for (i = 2; i < NF; i++) { print $i } }' Dockerfile))"
 		echo
 		for va in "${versionAliases[@]}"; do