Test in Go 1.20

Author: mislav

.github/workflows/push.yml

@@ -5,7 +5,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go: [ '1.13', '1.15' ]
+        go: [ '1.14', '1.20' ]
         os: [ ubuntu-latest, macos-latest, windows-latest ]
       fail-fast: false