✨ Accept mail configuration options

refs TryGhost#232, TryGhost#216

- this is the most straight forward pass through adding mail config options
- there is loads of small tweaks possible here, but they are not required
E.g.
- auto-set transport to smtp if any other argument is supplied
- use grouping to make the output better
- stronger use of implies?

Author: ErisDS

lib/commands/config/advanced.js

@@ -7,6 +7,11 @@ const validator = require('validator');
 const url = require('url');
 
 const BASE_PORT = '2368';
+const knownMailServices = [
+    'AOL', 'DynectEmail', 'Gmail', 'hot.ee', 'Hotmail', 'iCloud', 'mail.ee', 'Mail.Ru', 'Mailgun',
+    'Mailjet', 'Mandrill', 'Postmark', 'QQ', 'QQex (Tencent Business Email)', 'SendGrid',
+    'SendCloud', 'SES', 'Yahoo', 'yandex', 'Zoho'
+];
 
 /*
     Note: these options are handled serially, i.e. one after the other.
@@ -58,6 +63,8 @@ module.exports = {
         defaultValue: (c, env) => env === 'production' ? 'systemd' : 'local',
         type: 'string'
     },
+
+    // Database options
     db: {
         description: 'Type of database Ghost should use',
         validate: value => includes(['sqlite3', 'mysql'], value),
@@ -89,6 +96,45 @@ module.exports = {
         configPath: 'database.connection.database',
         type: 'string'
     },
+
+    // Mail options:
+    // Designed to support the most common mail configs, more advanced configs will require editing the config file
+    mail: {
+        description: 'Mail transport, E.g SMTP, Sendmail or Direct',
+        validate: value => includes(['SMTP', 'Sendmail', 'Direct'], value),
+        configPath: 'mail.transport',
+        type: 'string',
+        default: 'Direct'
+    },
+    mailservice: {
+        description: 'Mail service (used with SMTP transport), E.g. Mailgun, Sendgrid, Gmail, SES...',
+        configPath: 'mail.options.service',
+        validate: value => includes(knownMailServices, value),
+        type: 'string'
+    },
+    mailuser: {
+        description: 'Mail auth user (used with SMTP transport)',
+        configPath: 'mail.options.auth.user',
+        type: 'string',
+        implies: 'mailpass'
+    },
+    mailpass: {
+        description: 'Mail auth pass (used with SMTP transport)',
+        configPath: 'mail.options.auth.pass',
+        type: 'string',
+        implies: 'mailuser'
+    },
+    mailhost: {
+        description: 'Mail host (used with SMTP transport)',
+        configPath: 'mail.options.host',
+        type: 'string'
+    },
+    mailport: {
+        description: 'Mail port (used with SMTP transport)',
+        configPath: 'mail.options.port',
+        type: 'number'
+    },
+
     sslemail: {
         description: 'SSL email address',
         configPath: 'ssl.email',