Project deploy keys API
Fix loading animation while browsing tree
System hooks API.
Update README with references to versions.
Use redis as cache storage. cache events
Merge pull request #3157 from cabello/patch-1

Update README with references to versions.
Merge pull request #3156 from m4tthumphrey/api-system-hooks

Added methods to manage system hooks from API
Merge pull request #3149 from m4tthumphrey/api-deploy-keys

Added methods to manage project deploy keys via API
Use secure protocol
Merge pull request #3158 from dosire/master

Use secure protocol
update Gemfile.lock with https rubygems
add system hooks api docs to help content
fix js syntax error
show highlighted code correctly inside issue body
Return project description back
Refactor: replace "render :json = graph.to_json" to view template(show.json.erb).

Because model shouldn't know about view logic.
Refactor: grouping parent and their space by including array.