Add inbucket docker image to allow local and automated testing of emails (#4901)

* add docker container for inbucket

* Add way to get the emails using inbucket and add a test for reset password

* add config setting to send emails

* update TestEmailTest

update

* add another test and fix wrong assert

* update per review

fix lint

change senders email

* Revert config.json to default values for EmailSettings section

* update test

* add setup to make the test run

api/user_test.go

@@ -1284,6 +1284,9 @@ func TestResetPassword(t *testing.T) {
 	LinkUserToTeam(user, team)
 	store.Must(app.Srv.Store.User().VerifyEmail(user.Id))
 
+	//Delete all the messages before check the reset password
+	utils.DeleteMailBox(user.Email)
+
 	Client.Must(Client.SendPasswordReset(user.Email))
 
 	var recovery *model.PasswordRecovery
@@ -1293,6 +1296,19 @@ func TestResetPassword(t *testing.T) {
 		recovery = result.Data.(*model.PasswordRecovery)
 	}
 
+	//Check if the email was send to the rigth email address and the recovery key match
+	if resultsMailbox, err := utils.GetMailBox(user.Email); err != nil && !strings.ContainsAny(resultsMailbox[0].To[0], user.Email) {
+		t.Fatal("Wrong To recipient")
+	} else {
+		if resultsEmail, err := utils.GetMessageFromMailbox(user.Email, resultsMailbox[0].ID); err == nil {
+			if !strings.Contains(resultsEmail.Body.Text, recovery.Code) {
+				t.Log(resultsEmail.Body.Text)
+				t.Log(recovery.Code)
+				t.Fatal("Received wrong recovery code")
+			}
+		}
+	}
+
 	if _, err := Client.ResetPassword(recovery.Code, ""); err == nil {
 		t.Fatal("Should have errored - no password")
 	}