change binary to certbot
out of the certbot/certbot README.rst:
> Until May 2016, Certbot was named simply letsencrypt or letsencrypt-auto, depending on install method. Instructions on the Internet, and some pieces of the software, may still refer to this older name.
@@ -13,7 +13,7 @@ Let's Encrypt is a free Certificate Authority that makes it easy to secure your
0: Prerequisites
================
* Install Synapse_.
-* Install (or Download) `Let's Encrypt`_
+* Install (or Download) `certbot`_
1: Get certificates
===================
@@ -23,11 +23,11 @@ Also, the certificates will be in a folder under /etc/letsencrypt (see below) an
::
-# letsencrypt-auto certonly --standalone
+# certbot certonly --standalone
A note about renewal
--------------------
-These certificates will expire in 3 months. To renew certificates, run ```letsencrypt-auto renew```. It is recommended to create a cronjob, which attempts renewal twice a day. Depending on your distribution, that could be already configured.
+These certificates will expire in 3 months. To renew certificates, run ```certbot renew```. It is recommended to create a cronjob, which attempts renewal twice a day. Depending on your distribution, that could be already configured.
2: Install Certificates
=======================
