Merge pull request #4 from AlexChien/master

add user-agent
Add version to user agent
Add accept header
Bump version to 0.2.0
add new fixtures to match new mtgox api, and update spec to match
update spec on cancel to match new OIDs
actually sort the offers
Merge pull request #5 from YenTheFirst/master

update specs to match new API, and implement some of the necessary changes
Fix specs
Parse date in order response
Bump version to 0.3.0
Raise custom error when response has a 200 status
Bump version to 0.3.1
Show parsed date in documentation
DRY up order parsing
Add commission
Bump version to 0.4.0
Parse amount and price
Bump version to 0.4.1
More explicit requirements