updated Makefile.

Makefile

@@ -1,11 +1,18 @@
 OPENRESTY_PREFIX=/usr/local/openresty-debug
-.PHONY: all test
 
-all: ;
+PREFIX ?=          /usr/local
+LUA_INCLUDE_DIR ?= $(PREFIX)/include
+LUA_LIB_DIR ?=     $(PREFIX)/lib/lua/$(LUA_VERSION)
+INSTALL ?= install
 
-test:
-	PATH=$(OPENRESTY_PREFIX)/nginx/sbin:$$PATH prove -I../test-nginx/lib -r t
+.PHONY: all test install
+
+all: ;
 
 install: all
-	cp -r lib/resty $(OPENRESTY_PREFIX)/lualib/
+	$(INSTALL) -d $(DESTDIR)/$(LUA_LIB_DIR)/resty
+	$(INSTALL) lib/resty/*.lua $(DESTDIR)/$(LUA_LIB_DIR)/resty
+
+test: all
+	PATH=$(OPENRESTY_PREFIX)/nginx/sbin:$$PATH prove -I../test-nginx/lib -r t