Certificate file name extensions unified (#354)

* Fix for default smtp certificate name

This fixes the defaut smtp certificate file name from smtp.crt to smtp.cert as it is used throughout the postal code.

config/postal.defaults.yml

@@ -66,7 +66,7 @@ workers:
 smtp_server:
   port: 25
   tls_enabled: false
-  tls_certificate_path: # Defaults to config/smtp.crt
+  tls_certificate_path: # Defaults to config/smtp.cert
   tls_private_key_path: # Defaults to config/smtp.key
   proxy_protocol: false
   log_connect: true

resource/nginx.cfg

@@ -10,7 +10,7 @@ server {
     listen 0.0.0.0:443 ssl;
     root /opt/postal/app/public;
     server_name postal.yourdomain.com;
-    ssl_certificate      ssl/postal.crt;
+    ssl_certificate      ssl/postal.cert;
     ssl_certificate_key  ssl/postal.key;
 
     # Generate using: openssl dhparam 4096 -out /etc/ssl/dhparam.pem

script/install/ubuntu1604.sh

@@ -67,7 +67,7 @@ postal start
 #
 cp /opt/postal/app/resource/nginx.cfg /etc/nginx/sites-available/default
 mkdir /etc/nginx/ssl/
-openssl req -x509 -newkey rsa:4096 -keyout /etc/nginx/ssl/postal.key -out /etc/nginx/ssl/postal.crt -days 365 -nodes -subj "/C=GB/ST=Example/L=Example/O=Example/CN=example.com"
+openssl req -x509 -newkey rsa:4096 -keyout /etc/nginx/ssl/postal.key -out /etc/nginx/ssl/postal.cert -days 365 -nodes -subj "/C=GB/ST=Example/L=Example/O=Example/CN=example.com"
 service nginx reload
 
 #