How to work around verification codes for test users on LinkedIn

I have some Selenium tests running on Elastic Bamboo. I've created a test user account on LinkedIn and I am using it to log in to the site I am testing.

But sometimes the automatic tests fail, because the user cannot authenticate on LinkedIn, receiving this email message:

Subject:    Test, here's your PIN
Date:   Wed, 6 May 2015 08:05:11 +0000 (UTC)
From:   LinkedIn Security <security-noreply@linkedin.com>
To:     Test Bot <...>

Hi Test,

We noticed someone just tried to sign in to your LinkedIn account from a
location you haven't used before, so we want to make sure it's really you.

If you did try to sign in:
Please use this verification code to complete your sign in: 310197
...

I could not find any setting on LinkedIn to disable this security feature.

Changing the Elastic image configuration to always use the same availability zone didn't help.