Removing unused imports, stale code, and adding/removing whitespaces
Remove dead code

Got rid of a function by using astropy.extern.six
Removed a fix_header function that appears superfluous
Merge pull request #1 from sargas/remove-dead-code
clean up tests
clean up cython file
minor fixes
Addressing comments
Merge pull request #51 from bsipocz/code_cleanup

Code cleanup