Make host URL dynamic in reset password email

[enricostano]

We need to be able to use https://staging.timeoverflow.org when running the app in staging.

I, [2018-05-28T09:16:07.655208 #30936]  INFO -- :   Rendered devise/mailer/reset_password_instructions.html.erb (2.6ms)
D, [2018-05-28T09:16:08.243788 #30936] DEBUG -- : 
Devise::Mailer#reset_password_instructions: processed outbound mail in 618.3ms
I, [2018-05-28T09:16:08.264918 #30936]  INFO -- : 
Sent mail to enricostn@gmail.com (20.0ms)
D, [2018-05-28T09:16:08.265651 #30936] DEBUG -- : Date: Mon, 28 May 2018 09:16:08 +0000
From: info@timeoverflow.org
Reply-To: info@timeoverflow.org
To: enricostn@gmail.com
Message-ID: <5b0bc8d83e8e5_78d82b0b6332712c84027@scw-064c30.mail>
Subject: Reset password instructions
Mime-Version: 1.0
Content-Type: text/html;
 charset=UTF-8
Content-Transfer-Encoding: 7bit

<p>Hello enricostn@gmail.com!</p>

<p>Someone has requested a link to change your password. You can do this through the link below.</p>

<p><a href="https://www.timeoverflow.org/users/password/edit?reset_password_token=6Lzsh2VVsbyzdPhk6myz">Change my password</a></p>

<p>If you didn't request this, please ignore this email.</p>
<p>Your password won't change until you access the link above and create a new one.</p>

[markets]

@enricostano @sauloperez I think we can close this one too

[sauloperez]

I believe so. @sseerrggii you've been the last to try things in staging. can you confirm?

[sseerrggii]

Mmm 🤔

When I'm testing #401 on staging.timeoverflow.org it still send mails with links to www.timeoverflow.org, I tried weekly digest and Devise mails.

[sauloperez]

Fuuu I believe we changed the provisioning config so it picks up a different hostname in staging 🙈 We'll need to check again.

[sseerrggii]

What are the next steps here @sauloperez ?

[sauloperez]

We need to investigate again where does the hostname used in emails come from. I remember fixing it not long ago.

[markets]

It just happened to me playing in staging, maybe @konykon can help us with this one? In theory, this ENV var should do the trick:

timeoverflow/config/environments/production.rb

Line 76 in adcfb26

host: ENV["MAIL_LINK_HOST"],