Pipeline completion e-mails do not display well when images are not shown

Summary

Pipeline completion e-mail do not display well in GMail when images are not shown. This makes the information hard to read because the alt-text overlaps other content.

Steps to reproduce

Ensure GMail is not configured to display images from GitLab ((instructions for disabling if they are configured to always display)[http://www.prowebguru.com/2015/04/how-to-disable-always-display-images-from-in-gmail/#.WKcCelfR37g]). Open an existing pipleine completion mail or take an action causing a new one to be sent and open it.

What is the current bug behavior?

Image alt-text does not flow well in the layout causing content to be hard to read due to ovelap.

What is the expected correct behavior?

No text should overlap and the layout should look clean when images are not displayed.

Relevant logs and/or screenshots

Firefox 51.0.1 (64-bit)
Linux Mint 18.1

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

N/A

Results of GitLab application Check

N/A

Possible fixes

https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/views/notify/pipeline_success_email.html.haml
https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/views/notify/pipeline_failed_email.html.haml

The simplest solution would to just remove the alt-text for Branch icon, Commit icon, and Avatar. Alternatively, the layout could be changed to better render the alt-text.