Fix user list sorting
User: Set name to GitHub handle if no name was provided, to ensure consistent sorting
User: set location to nil when no location was set by the user
Cleanup
Ensure sanitized name will not be overriden by empty GH name
Sanitize location before save
Preset name before checking against empty target value
Unfold ternary statement
Merge pull request #88 from rails-girls-summer-of-code/fix-user-sorting

Fix user sorting