add debug to Makefile

Makefile

@@ -2,6 +2,10 @@ all:
 	mkdir -p out
 	gcc -I/usr/local/include -I~/Downloads/libuv-0.10.12/include ./src/main.c -o ./out/fast-cache -L/usr/local/lib -luv -lkyotocabinet -lcurl
 
+debug:
+	mkdir -p out
+	gcc -I/usr/local/include -I~/Downloads/libuv-0.10.12/include ./src/main.c -o ./out/fast-cache -L/usr/local/lib -luv -lkyotocabinet -lcurl -g
+
 run:
 	./out/fast-cache