Add musl libc option for prebuilding on linux

Useful for alpine linux, and other distros using musl

Author: dhritzkiv

scripts/after_success.sh

@@ -15,4 +15,8 @@ PACKAGE_JSON_VERSION=$(node -e "console.log(require('./package.json').version)")
 if [[ ${COMMIT_MESSAGE} == ${PACKAGE_JSON_VERSION} ]]; then
   echo "running prebuild"
   node ./node_modules/prebuild/bin.js -t 8.0.0 -t 9.0.0 -t 10.0.0 -t 11.0.0 -t 12.0.0 --strip -u ${GITHUB_TOKEN}
+  
+  if [[ ${TRAVIS_OS_NAME} == "linux" ]]; then
+    node ./node_modules/prebuild/bin.js --libc=musl -t 8.0.0 -t 9.0.0 -t 10.0.0 -t 11.0.0 -t 12.0.0 --strip -u ${GITHUB_TOKEN}
+  fi
 fi