Add Account resource
Add settlements resource
Add settle method to accounts
edit tests for settlements
Edit account to sweep_account
Edit name of sweep account to payable_account
Edit account resource to save settlement and update tests
change customer helper method to type rather than account_type for payable account
PEP8
Account and Settlement guide snippets
Merge remote-tracking branch 'origin/accounts_settlements' into accounts_settlements
Merge pull request #135 from balanced/accounts_settlements

Accounts & settlements