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

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.
- `nolintlint_unused.go` testdata is not matching regex. Correct by adding one
space after //

[1]: golang/go#40763

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

Author: sayboras

.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
 }