[doc] Update pre-requiste (based on feedback https://github.com/ros-industrial/industrial_ci/pull/234#discussion_r160665709).
[doc] Update pre-requiste (based on feedback https://github.com/ros-industrial/industrial_ci/pull/234#discussion_r160665709).

ros-industrial/industrial_ci,ros-industrial/industrial_ci,ros-industrial/industrial_ci