update openresty for CI

Author: idevz

.travis/setup_servers.sh

@@ -2,14 +2,14 @@
 
 # A script for setting up environment for travis-ci testing.
 # Sets up openresty.
-OPENRESTY_VERSION="1.9.3.1"
+OPENRESTY_VERSION="1.9.15.1"
 OPENRESTY_DIR=$TRAVIS_BUILD_DIR/install/openresty
 
 #if [ "$LUA" == "lua5.1" ]; then
 #	luarocks install LuaBitOp
 #fi
 
-wget https://openresty.org/download/ngx_openresty-$OPENRESTY_VERSION.tar.gz
+wget https://openresty.org/download/openresty-$OPENRESTY_VERSION.tar.gz
 tar xzvf ngx_openresty-$OPENRESTY_VERSION.tar.gz
 cd ngx_openresty-$OPENRESTY_VERSION/