smtp + email confirmation (#285)

* add smtp configuration

* add email confirm + reset templates

* add email sender to testrig

* flesh out the email sender interface

* go fmt

* golint

* update from field with more clarity

* tidy up the email formatting

* fix tests

* add email sender to processor

* tidy client api processing a bit

* further tidying in fromClientAPI

* pin new account to user

* send msg to processor on new account creation

* generate confirm email uri

* remove emailer from account processor again

* add processCreateAccountFromClientAPI

* move emailer accountprocessor => userprocessor

* add email sender to user processor

* SendConfirmEmail function

* add noop email sender

* use noop email sender in tests

* only assemble message if callback is not nil

* use noop email sender if no smtp host is defined

* minify email html before sending

* fix wrong email address

* email confirm test

* fmt

* serve web hndler

* add email confirm handler

* init test log properly on testrig

* log emails that *would* have been sent

* go fmt ./...

* unexport confirm email handler

* updatedAt

* test confirm email function

* don't allow tokens older than 7 days

* change error message a bit

* add basic smtp docs

* add a few more snippets

* typo

* add email sender to outbox tests

* don't use dutch wikipedia link

* don't minify email html

testrig/email.go

@@ -0,0 +1,42 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package testrig
+
+import "github.com/superseriousbusiness/gotosocial/internal/email"
+
+// NewEmailSender returns a noop email sender that won't make any remote calls.
+//
+// If sentEmails is not nil, the noop callback function will place sent emails in
+// the map, with email address of the recipient as the key, and the value as the
+// parsed email message as it would have been sent.
+func NewEmailSender(templateBaseDir string, sentEmails map[string]string) email.Sender {
+	var sendCallback func(toAddress string, message string)
+
+	if sentEmails != nil {
+		sendCallback = func(toAddress string, message string) {
+			sentEmails[toAddress] = message
+		}
+	}
+
+	s, err := email.NewNoopSender(templateBaseDir, sendCallback)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}