MINOR: spoe: add random ip-reputation service as SPOA example

This is a very simple service that implement a "random" ip reputation
service. It will return random scores for all checked IP addresses. It only
shows you how to implement a ip reputation service or such kind of services
using the SPOE.
diff --git a/contrib/spoa_example/Makefile b/contrib/spoa_example/Makefile
new file mode 100644
index 0000000..e6b7c53
--- /dev/null
+++ b/contrib/spoa_example/Makefile
@@ -0,0 +1,24 @@
+DESTDIR =
+PREFIX  = /usr/local
+BINDIR  = $(PREFIX)/bin
+
+CC = gcc
+LD = $(CC)
+
+CFLAGS  = -g -O2 -Wall -Werror -pthread
+LDFLAGS = -lpthread
+
+OBJS = spoa.o
+
+
+spoa: $(OBJS)
+	$(LD) $(LDFLAGS) -o $@ $^
+
+install: spoa
+	install spoa $(DESTDIR)$(BINDIR)
+
+clean:
+	rm -f spoa $(OBJS)
+
+%.o:	%.c
+	$(CC) $(CFLAGS) -c -o $@ $<