refactor, use dict.items() to get data better
refactor: make .get_feed not touch self.feed
add fieldnames property that stores fields used in the sheet
add make todo
change .add_row to .append
add initial setup.py
fix getting default worksheet was broken

at the cost of always looking up all all the worksheets. This way
worksheet is always set and resembles something like od6, od7...
update: set worksheet to 'default' if not specified
make the write test append the version
call this version 0.1.0

even though it's been that in setup.py. Meh.