Add Makefile to check the following thing (#947)

* Add Makefile to check the following thing.

* vet check
* fmt check
* embedmd check
* misspell check

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* remove unused variable.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

Makefile

@@ -0,0 +1,61 @@
+GOFMT ?= gofmt "-s"
+PACKAGES ?= $(shell go list ./... | grep -v /vendor/)
+GOFILES := $(shell find . -name "*.go" -type f -not -path "./vendor/*")
+
+all: build
+
+install: deps
+	govendor sync
+
+.PHONY: test
+test:
+	go test -v -covermode=count -coverprofile=coverage.out
+
+.PHONY: fmt
+fmt:
+	$(GOFMT) -w $(GOFILES)
+
+.PHONY: fmt-check
+fmt-check:
+	# get all go files and run go fmt on them
+	@diff=$$($(GOFMT) -d $(GOFILES)); \
+	if [ -n "$$diff" ]; then \
+		echo "Please run 'make fmt' and commit the result:"; \
+		echo "$${diff}"; \
+		exit 1; \
+	fi;
+
+vet:
+	go vet $(PACKAGES)
+
+deps:
+	@hash govendor > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
+		go get -u github.com/kardianos/govendor; \
+	fi
+	@hash embedmd > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
+		go get -u github.com/campoy/embedmd; \
+	fi
+
+embedmd:
+	embedmd -d *.md
+
+.PHONY: lint
+lint:
+	@hash golint > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
+		go get -u github.com/golang/lint/golint; \
+	fi
+	for PKG in $(PACKAGES); do golint -set_exit_status $$PKG || exit 1; done;
+
+.PHONY: misspell-check
+misspell-check:
+	@hash misspell > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
+		go get -u github.com/client9/misspell/cmd/misspell; \
+	fi
+	misspell -error $(GOFILES)
+
+.PHONY: misspell
+misspell:
+	@hash misspell > /dev/null 2>&1; if [ $$? -ne 0 ]; then \
+		go get -u github.com/client9/misspell/cmd/misspell; \
+	fi
+	misspell -w $(GOFILES)