feat: Add support for Node 16, 18, remove support for Node 12, 15 (#189)

BREAKING CHANGE: Removes support for Node 12 and 15 which have reached their End-of-Life date and are not officially maintained anymore.

Author: mtrezza

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [ '12', '14', '15' ]
+        node: [ '14', '16', '18' ]
     timeout-minutes: 30
     env:
       COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}