Changing cookbook/ deployment  info

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |  

Added  info  in cookbook in  deployment  about  checking  server requirements  php app/check.php
hmm, actually, the rebase is totally messy: the upstream commits have been rebased instead of rebasing the branch on top of upstream commits. Look at the list of commits in the PR. This is why this appears in the diff