Including golangci-lint and updating go

Author: rafaelrubbioli

.travis.yml

@@ -1,10 +1,11 @@
 language: go
 go:
-  - 1.8
+  - 1.13.x
 go_import_path: github.com/StudioSol/async
 install:
   - make dependency
 script:
+  - make lint
   - make test
 after_success:
   - bash <(curl -s https://codecov.io/bash)

Makefile

@@ -8,3 +8,7 @@ test:
 		go test -race -v -coverprofile=profile.out -covermode=atomic $$d || exit 1; \
 		[ -f profile.out ] && cat profile.out >> coverage.txt && rm profile.out; \
 	done
+
+lint:
+	go get -u github.com/golangci/golangci-lint/cmd/golangci-lint
+	golangci-lint run --enable golint --enable gocyclo