test for datafinder
added sorting
added test for sorting, fixed tuples
PEP8 and fixed out_paths sort
order matters when you do sorting
TST+BF: Improve DataFinder tests, fix issue with unpack_single and sorting
Merge pull request #6 from moloney/enh-df-tests-rebase

TST+BF: Improve DataFinder tests, fix issue with unpack_single and sorti...
Merge pull request #765 from chrisfilo/enh/datafinder_test

Test and sorting for DataFinder