upgrade golangci-lint

golangci/golangci-lint#663

Author: temoto

.travis.yml

@@ -13,7 +13,7 @@ env:
   - GO111MODULE=on
 
 install:
-  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | bash -s -- -b $GOPATH/bin v1.16.0
+  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | bash -s -- -b $GOPATH/bin v1.19.1
 
 script:
   - go fmt ./...