travis: use personal lua-nginx-module to pass test

Author: detailyang

.travis.yml

@@ -56,7 +56,7 @@ install:
   - git clone https://github.com/openresty/openresty.git ../openresty
   - git clone https://github.com/openresty/openresty-devel-utils.git
   - git clone https://github.com/simpl/ngx_devel_kit.git ../ndk-nginx-module
-  - git clone https://github.com/openresty/lua-nginx-module.git ../lua-nginx-module
+  - git clone -b lua-ffi-api-sslctx https://github.com/detailyang/lua-nginx-module.git ../lua-nginx-module
   - git clone https://github.com/openresty/no-pool-nginx.git ../no-pool-nginx
   - git clone https://github.com/openresty/echo-nginx-module.git ../echo-nginx-module
   - git clone https://github.com/openresty/lua-resty-lrucache.git