style(rubocop): fix all safe auto correctable offenses

app/mailers/app_mailer.rb

@@ -2,50 +2,50 @@ class AppMailer < ApplicationMailer
 
   def verify_email_address(user)
     @user = user
-    mail :to => @user.email_address, :subject => "Verify your new e-mail address"
+    mail to: @user.email_address, subject: "Verify your new e-mail address"
   end
 
   def new_user(user)
     @user = user
-    mail :to => @user.email_address, :subject => "Welcome to Postal"
+    mail to: @user.email_address, subject: "Welcome to Postal"
   end
 
   def user_invite(user_invite, organization)
     @user_invite = user_invite
     @organization = organization
-    mail :to => @user_invite.email_address, :subject => "Access the #{organization.name} organization on Postal"
+    mail to: @user_invite.email_address, subject: "Access the #{organization.name} organization on Postal"
   end
 
   def verify_domain(domain, email_address, user)
     @domain = domain
     @email_address = email_address
     @user = user
-    mail :to => email_address, :subject => "Verify your ownership of #{@domain.name}"
+    mail to: email_address, subject: "Verify your ownership of #{@domain.name}"
   end
 
   def password_reset(user, return_to = nil)
     @user = user
     @return_to = return_to
-    mail :to => @user.email_address, :subject => "Reset your Postal password"
+    mail to: @user.email_address, subject: "Reset your Postal password"
   end
 
   def server_send_limit_approaching(server)
     @server = server
-    mail :to => @server.organization.notification_addresses, :subject => "[#{server.full_permalink}] Mail server is approaching its send limit"
+    mail to: @server.organization.notification_addresses, subject: "[#{server.full_permalink}] Mail server is approaching its send limit"
   end
 
   def server_send_limit_exceeded(server)
     @server = server
-    mail :to => @server.organization.notification_addresses, :subject => "[#{server.full_permalink}] Mail server has exceeded its send limit"
+    mail to: @server.organization.notification_addresses, subject: "[#{server.full_permalink}] Mail server has exceeded its send limit"
   end
 
   def server_suspended(server)
     @server = server
-    mail :to => @server.organization.notification_addresses, :subject => "[#{server.full_permalink}] Your mail server has been suspended"
+    mail to: @server.organization.notification_addresses, subject: "[#{server.full_permalink}] Your mail server has been suspended"
   end
 
   def test_message(recipient)
-    mail :to => recipient, :subject => "Postal SMTP Test Message"
+    mail to: recipient, subject: "Postal SMTP Test Message"
   end
 
 end