Issue #14 path in role.rb is wrong - change code

* removed invalid alternative pathj to roles.yml in
app/models/cms/fortress/role.rb and added exception
handling, if the file is not found.
* add error message css
* add Exception folder ibn models with exception
MissingRoleCconfigurationFile
Merge pull request #15 from andywenk/new-role-new-yml-file-exception-handling

Issue #14 path in role.rb is wrong - change code