build(golang1.15): Upgrade to golang 1.15 for smaller binary (#1303)

Golang 1.15 comes to few improvements, one of them is to have smaller
binary.

This PR is to make golang 1.15 as default version in CI, I also update
Docker based image to golang:1.15* as well.

Two issues faced with golang 1.15:
- Conflict between -v in `golangci-lint` and `go test`. Update to --verbose
to avoid the same. [1]
- `nolintlint_unused.go` testdata is not matching regex. Correct by adding one
space after //

[1]: https://github.com/golang/go/issues/40763

Signed-off-by: Tam Mach <sayboras@yahoo.com>

.github/workflows/pr.yml

@@ -26,7 +26,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.14 # test only the latest go version to speed up CI
+          go-version: 1.15 # test only the latest go version to speed up CI
       - name: Run tests
         run: make.exe test
         continue-on-error: true
@@ -38,7 +38,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.14 # test only the latest go version to speed up CI
+          go-version: 1.15 # test only the latest go version to speed up CI
       - name: Run tests
         run: make test
         continue-on-error: true
@@ -50,6 +50,7 @@ jobs:
         golang:
           - 1.13
           - 1.14
+          - 1.15
     steps:
       - uses: actions/checkout@v2
       - name: Install Go
@@ -77,6 +78,6 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.14
+          go-version: 1.15
       - name: Check generated files are up to date
         run: make fast_check_generated

.github/workflows/tag.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.14
+          go-version: 1.15
       - name: Unshallow
         run: git fetch --prune --unshallow
       - name: Login do docker.io

build/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.14
+FROM golang:1.15
 
 # don't place it into $GOPATH/bin because Drone mounts $GOPATH as volume
 COPY golangci-lint /usr/bin/

build/Dockerfile.alpine

@@ -1,4 +1,4 @@
-FROM golang:1.14-alpine
+FROM golang:1.15-alpine
 
 # gcc is required to support cgo;
 # git and mercurial are needed most times for go get`, etc.

test/enabled_linters_test.go

@@ -176,7 +176,7 @@ func TestEnabledLinters(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			t.Parallel()
 
-			runArgs := []string{"-v"}
+			runArgs := []string{"--verbose"}
 			if !c.noImplicitFast {
 				runArgs = append(runArgs, "--fast")
 			}

test/testdata/nolintlint_unused.go

@@ -5,7 +5,7 @@ package testdata
 import "fmt"
 
 func Foo() {
-	fmt.Println("unused")          //nolint // ERROR "directive `//nolint .*` is unused"
-	fmt.Println("unused,specific") //nolint:varcheck // ERROR "directive `//nolint:varcheck .*` is unused for linter varcheck"
-	fmt.Println("not run")         //nolint:unparam // unparam is not run so this is ok
+	fmt.Println("unused")          // nolint // ERROR "directive `//nolint .*` is unused"
+	fmt.Println("unused,specific") // nolint:varcheck // ERROR "directive `//nolint:varcheck .*` is unused for linter varcheck"
+	fmt.Println("not run")         // nolint:unparam // unparam is not run so this is ok
 }