Added username to the User factory.
Added Travis build file.
Install Django first for the travis build.
Refactored the invoice creation view and added a check on invoice permissions.
Added the owner to the invoice.
Added chosen widget.
Hook to add extra css files.
Added the CC field
Added the django guardian properties to the invoice admin.
Moved the CC to use Chosen widget.
Merge remote-tracking branch 'origin/develop'