Docs: update DevOps stages

Requested by Mark P (https://gitlab.slack.com/archives/C16HYA2P5/p1540400685000100).

Update the stages https://docs.gitlab.com/ee/README.html#complete-devops-with-gitlab from:

Screen_Shot_2018-10-24_at_19.14.37

To:

Screen_Shot_2018-10-24_at_19.15.11

With all the content, ofc.

cc/ @gl-docsteam

Edited by Marcia Ramos