Orphan Excel Importer

Part of Jira story: https://osraav.atlassian.net/browse/OSRA-70

Task: https://osraav.atlassian.net/browse/OSRA-163

- Using roo gem to parse Excel files
- Using rails_config gem to read yaml configuration settings for the importer
This won't branch correctly. If `val.nil?` is true and `col.mandatory` is false then I don't want to execute the block starting at L66, instead I just want to skip processing this column.

I know this can be achieved using:

`if val.nil? && col.mandatory
   .....
elsif !val.nil?
   .....`

But I find it easier to read the way I originally wrote it. What do you think?