remove ./kong directory (#77)

diff --git a/Makefile b/Makefile
index 04c3f8c..2543766 100644
--- a/Makefile
+++ b/Makefile
@@ -37,7 +37,6 @@
 .PHONY: release-src
 release-src:
 	tar -zcvf $(RELEASE_SRC).tgz \
-	    ./kong \
 		./examples \
 		./licenses \
 		./rockspec \