Dropped unused makefile

Makefile

@@ -1,34 +0,0 @@
-.PHONY: all clean deps fmt vet test docker
-
-EXECUTABLE ?= drone-github-release
-IMAGE ?= plugins/$(EXECUTABLE)
-COMMIT ?= $(shell git rev-parse --short HEAD)
-
-LDFLAGS = -X "main.buildCommit=$(COMMIT)"
-PACKAGES = $(shell go list ./... | grep -v /vendor/)
-
-all: deps build test
-
-clean:
-	go clean -i ./...
-
-deps:
-	go get -t ./...
-
-fmt:
-	go fmt $(PACKAGES)
-
-vet:
-	go vet $(PACKAGES)
-
-test:
-	@for PKG in $(PACKAGES); do go test -cover -coverprofile $$GOPATH/src/$$PKG/coverage.out $$PKG || exit 1; done;
-
-docker:
-	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -ldflags '-s -w $(LDFLAGS)'
-	docker build --rm -t $(IMAGE) .
-
-$(EXECUTABLE): $(wildcard *.go)
-	go build -ldflags '-s -w $(LDFLAGS)'
-
-build: $(EXECUTABLE)