add makefile for some convenient commands

Makefile

@@ -0,0 +1,14 @@
+.PHONY: test
+
+# runs all necessary tests
+test:
+	@sh -c 'if [ ! -z "$(go fmt ./...)" ]; then exit 1; fi'
+	golint ./...
+	go vet ./...
+	go test ./...
+	go run cmd/godog/main.go -f progress
+
+# updates dependencies
+deps:
+	go get -u golang.org/x/tools/imports
+	go get -u github.com/shiena/ansicolor