Update installation.md

Additional unicorn -> puma reference update
Add seeds and improve ui. Remove snippet expires_at
Improve UI for project snippets
Minor ui fix for snippet
Merge pull request #4564 from mpwoodward/patch-2

Update installation.md
User links to user snippets
Use gitlab-shell authorized_keys truncation. Fix issue with authorized_keys stored in different location
Revert "Update installation.md"

This reverts commit b5cd66d41de98c63fdb048e3d0ce600c9353e230.
Revert "Update installation.md"

This reverts commit 670e1be7a402b1340393d298c7ebc05930ed7ac3.
Merge branch 'master' of github.com:gitlabhq/gitlabhq
Fix tests
Merge branch 'improve/snippets' of /home/git/repositories/gitlab/gitlabhq
Allow the ldap logins with email or username

Change-Id: I73b4aa4c46afd56ae02fb24abcd673c0724547e4
Update the proc/lamda to be consistent

Change-Id: I411c7544c7834b00d26e51dc9a6c0396c51bd4f3
Default allow username or email login to false

-If not specified in the gitlab.yml default this setting to false

Change-Id: I3551df364498dd84ccbd18c90797522e77159f05
Refer to recipes for nginx alternatives
Merge pull request #4289 from karlhungus/feature-ldap-signin-with-email-or-username

Allow the ldap logins with email or username
Merge branch 'nginx_alternatives_in_recipes' of /home/git/repositories/gitlab/gitlabhq
Doc for update from 5.3 to 5.4
Replace vim by editor