add Go 1.15.x, drop 1.13.x

Author: mvdan

.github/workflows/test.yml

@@ -4,7 +4,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.13.x, 1.14.x]
+        go-version: [1.14.x, 1.15.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
@@ -26,7 +26,7 @@ jobs:
     - name: Install Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.14.x
+        go-version: 1.15.x
     - name: Checkout code
       uses: actions/checkout@v2
       with:

README.md

@@ -13,7 +13,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.13.x, 1.14.x]
+        go-version: [1.14.x, 1.15.x]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:

go.mod

@@ -1,3 +1,3 @@
 module dummy.module/actions
 
-go 1.13
+go 1.14