do a start transaction as well

When adding verify to the sample boku script, I noticed that in the case of a pending service id, sample-boku.py failed on the last step. So this:
* does the standard verification
* then tries to start a fake transaction

To see this in action, checkout the changes to boku-basic.py, you'll see this for the service id mentioned in bug 1014239.

```
Starting a transaction
Calling url: http://localhost:8001/boku/transactions/ <function post at 0x10a9afb18>
Request data:
{'callback_url': 'http://testing.com/notification',
 'country': 'MX',
 'forward_url': 'http://testing.com/result',
 'price': '15.00',
 'seller_uuid': '5906b9a8-e171-462c-99e3-7212b525786d',
 'transaction_uuid': 'cd1d326d-874d-469c-8792-c21f3475d68e',
 'user_uuid': 'dfb4e4b9-6c35-48a5-a215-e69ecac699a5'}
Status code: 500
Error:
{u'error_code': u'BokuException',
 u'error_data': {},
 u'error_message': u'API Error: 34 Invalid Or Missing Service-Id'}
```