Merge pull request #363 from kzys/go-113

Drop Go 1.13

Author: kzys

.github/workflows/go.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go: ['1.13', '1.14', '1.15', '1.16', '1.17']
+        go: ['1.14', '1.15', '1.16', '1.17']
         os: ['ubuntu-18.04', 'ubuntu-20.04']
       fail-fast: false
     name: ${{ matrix.os }} / Go ${{ matrix.go }}