Deploy git-lfs on devserver and shellserver roles

Summary:
GitHub introduced a standard format for file storage called git-lfs.

Phabricator now supports git-lfs.

As rRAIN could benefit of git-lfs support to store multimedia files,
it seems to be the ideal moment to deploy this.

This change installs the git-lfs command in servers used for Git operations.

Ref T1355

Test Plan:

• git lfs track "*.mp4"
• git add somevideo.mp4

Reviewers: dereckson

Maniphest Tasks: T1355

Differential Revision: https://devcentral.nasqueron.org/D1386