Make Makefile a bit more general

A tiny bit.

Makefile

@@ -8,7 +8,7 @@ all: $(NAME)
$(NAME): $(WORKSPACE) $(SOURCES)
	cd $(WORKSPACE) && go install -v $(NAMESPACE)
	cp $(GOPATH)/bin/$(NAME) $(PWD)
	cp $(GOPATH)/bin/$@ $(PWD)
$(WORKSPACE):
	mkdir -p $(shell dirname $(WORKSPACE))