Adding help to Makefile and updating make test target (#325)

add help and changed test target

Makefile

@@ -1,22 +1,24 @@
 .PHONY: all build clean vet test docgen
-
-all: clean test build
+all: clean test build ## Run everything
 
 BINDIR := ./bin
 BINNAME := witness
 BUILDFLAGS := -trimpath
 
-clean:
+clean: ## Clean the binary directory
 	rm -rf $(BINDIR)
 
 build:
 	CGO_ENABLED=0 go build $(BUILDFLAGS) -o $(BINDIR)/$(BINNAME) ./main.go
 
-vet:
+vet: ## Run go vet
 	go vet ./...
 
-test:
-	go test ./...
+test: ## Run go tests
+	go test -v -coverprofile=profile.cov -covermode=atomic ./...
 
-docgen:
+docgen: ## Generate the docs
 	go run ./docgen
+
+help: ## Display this help screen
+	@grep -h -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'