ci: add nodejs v16 to test matrix (#90)

Author: Fdawgs

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [10, 12, 14, 16]
 
     services:
       postgres: