Update nginx (#7)

* Update nginx to version 1.13.3

Security: a specially crafted request might result in an integer
verflow and incorrect processing of ranges in the range filter,
potentially resulting in sensitive information leak (CVE-2017-7529).

* Fix dead link

Author: Koki Yasuda

Dockerfile

@@ -2,7 +2,7 @@ FROM alpine:latest
 
 MAINTAINER orleika <admin@orleika.io>
 
-ARG NGINX_VERSION=1.13.1
+ARG NGINX_VERSION=1.13.3
 ARG LIBRESSL_VERSION=2.5.4
 ARG GPG_LIBRESSL="A1EB 079B 8D3E B92B 4EBD  3139 663A F51B D5E4 D8D5"
 ARG GPG_NGINX="B0F4 2533 73F8 F6F5 10D4  2178 520A 9993 A1C0 52F8"

README.md

@@ -1,9 +1,9 @@
 # Docker Nginx Image _(docker-nginx)_
 
 [![Build Status](https://img.shields.io/travis/orleika/docker-nginx/master.svg?style=flat-square)](https://travis-ci.org/orleika/docker-nginx)
-[![nginx](http://img.shields.io/badge/nginx-v1.13.1-blue.svg?style=flat-square)](https://nginx.org/en/download.html)
+[![nginx](http://img.shields.io/badge/nginx-v1.13.3-blue.svg?style=flat-square)](https://nginx.org/en/download.html)
 [![LibreSSL](http://img.shields.io/badge/LibreSSL-v2.5.4-blue.svg?style=flat-square)](https://www.libressl.org/)
-[![MIT License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat-square)](https://orleika.github.io/mit-license)
+[![MIT License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat-square)](https://github.com/orleika/docker-nginx/blob/master/LICENSE)
 
 > docker nginx image