Add a keys method to Stripe_Object for getting the list of keys

Fixes #42
support property deletion by setting NULL
fix typos in tests
remove indentation tabs
Merge pull request #48 from stripe/am-property-deletion

Support property deletion
Bump version
Add BalanceTransaction API resource.
s/tabs/spaces/
Pretend to have late static binding
Bump version to 1.8.3.
Missed semicolon while updating version.
Update LICENSE
add support for closing disputes
Merge pull request #51 from stripe/lg-dispute-close

Support for closing disputes
Migrate to simpletest/simpletest for unit tests
Metadata support
Bump version
Not ready yet.

This reverts commit bf7437988cb6e498b1323a04301fcebdf08ac6b0.
Merge branch 'master' into metadata
Revert "Not ready yet."

This reverts commit ba43d30fb8b9f8fc04ce24662fc5e27ff6744e89.