TST/API/BUG : test tifffile + fix bug found

 - add TiffStack_tifffile to api.py
 - set as default of no other reader found
 - add test
 - fix flip + transpose issue in reading images
MNT : PEP8 clean up + removed done todos
Merge pull request #105 from tacaswell/tifffile_tests

TST/API/BUG : test tifffile + fix bug found
REL : Tag v0.2.1