added csv_concat.rb and lib folder
Merge branch 'master' into csv_parsing
Merge branch 'master' of https://github.com/twurz/pcs_code_challenge_06
Merge pull request #4 from JulesVan/master

Merge pull request #2 from twurz/master
Merge pull request #3 from twurz/master

pulling Marko & Travis' changes