Add support for listing sets with `pulldown ls`.
Refactor the init method and do some tidying
Merge pull request #55 from jackfranklin/ls

Add support for listing sets with `pulldown ls`.
Add dry run functionality

This was more complex that expected. A bug in optimist means we have to
parse out the booleans ourselves, and then use them throughout.
Refactored a couple of methods to make this easier and clearer.
remove optimist
Merge pull request #56 from jackfranklin/dryru

Dry Runs (Closes #40)
move help into lib to tidy things up
move init to the top so it's ordered properly
move args parser into own file
move parse json method out
set up grunt for jshint
satisfy JSHint
add mocha to grunt
update the readme for the upcoming release
add global beforeEach and afterEach
set up test for zip
Fix zips not being sent to the right place
add test to cover -o on a regular file
Merge pull request #57 from jackfranklin/zips

Make sure zips honour the -o flag (Closes #41)
extract download method out