ci: test golang 1.16.x and 1.17.x too (#1425)

* ci: test golang 1.16.x too

* ci: style

* ci: test golang 1.17.x too

* bump go.mod to 1.15

* run gofmt

.github/workflows/Test.yml

@@ -18,29 +18,35 @@ jobs:
         - ubuntu
         - macOS
         go:
-        - 1.14.x
-        - 1.15.x
-    name: '${{ matrix.platform }} | ${{ matrix.go }}'
+        - 14
+        - 15
+        - 16
+        - 17
+    name: '${{ matrix.platform }} | 1.${{ matrix.go }}.x'
     runs-on: ${{ matrix.platform }}-latest
     steps:
 
     - uses: actions/setup-go@v2
       with:
-        go-version: ${{ matrix.go }}
+        go-version: 1.${{ matrix.go }}.x
 
     - uses: actions/checkout@v2
 
     - uses: actions/cache@v2
       with:
         path: ~/go/pkg/mod
-        key: ${{ runner.os }}-${{ matrix.go }}-${{ hashFiles('**/go.sum') }}
-        restore-keys: ${{ runner.os }}-${{ matrix.go }}-
+        key: ${{ runner.os }}-1.${{ matrix.go }}.x-${{ hashFiles('**/go.sum') }}
+        restore-keys: ${{ runner.os }}-1.${{ matrix.go }}.x-
 
     - run: |
         export GOBIN=$HOME/go/bin
         curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | bash -s -- -b $GOBIN latest
-        go install github.com/kyoh86/richgo
-        go install github.com/mitchellh/gox
+        case "${{ matrix.go }}" in
+          16|17) _version='@latest';;
+          *) _version='';;
+        esac
+        go install github.com/kyoh86/richgo"${_version}"
+        go install github.com/mitchellh/gox"${_version}"
 
     - run: PATH=$HOME/go/bin/:$PATH make
 

command_notwin.go

@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 package cobra

command_win.go

@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package cobra

go.mod

@@ -1,6 +1,6 @@
 module github.com/spf13/cobra
 
-go 1.14
+go 1.15
 
 require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.1