Added translations for Send Test Mail feature (#156)

* Added translations for Send Test Mail feature

locale/core.yml

@@ -107,6 +107,10 @@ core:
       mail_username_label: => core.ref.username
       mailgun_heading: Mailgun Settings
       not_sending_message: Flarum currently does not send emails. This can be due to the selected driver, or errors in its configuration.
+      send_test_mail_button: Send
+      send_test_mail_heading: Send Test Mail
+      send_test_mail_success: Test mail sent successfully!
+      send_test_mail_text: This will send an email using the above configuration to your email, {email}.
       smtp_heading: SMTP Settings
       submit_button: => core.ref.save_changes
       text: Configure the driver, settings and addresses your forum will use to send email.
@@ -541,6 +545,18 @@ core:
 
         If you do not wish to change your password, just ignore this email and nothing will happen.
 
+    # These translations are used when testing mailing configuration
+    send_test:
+      subject: Flarum Email Test
+      body: |
+        Hey {username}!
+
+        This is a test email to confirm that your Flarum email configuration is working properly.
+
+        If this was you, this email means that your configuration works!
+
+        If this was not you, please ignore this email.
+
   ##
   # REUSED TRANSLATIONS - These keys should not be used directly in code!
   ##