Run GitHub workflow in Node 14

And drop Node 8

Author: mroderick

.github/workflows/main.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [8, 10, 12]
+        node-version: [10, 12, 14]
 
     steps:
     - uses: actions/checkout@v1