Tests for Transactions

[grncdr]

Tests for:

• auto-rollback
• connections are returned to pool
• transactions unusable after rollback/commit
• no synchronous errors

Really, the Transaction might need to be rewritten using a better tested state machine library than the one I hacked up in a hurry. I'm open to recommendations if anybody has a preferred lib.

[brianc]

This is slightly off topic but postgres supports save points within transactions. Any thought to supporting those?

[grncdr]

I've thought about it, but it's probably a 1.x.y feature.

One option to consider would be putting the Transaction object into it's own module (it's pretty standalone already). This would make it easy for the drivers to implement .begin themselves and extend the Transaction object as necessary without depending on the connection pool bits.

That being said, I'm perfectly fine with having driver-specific Transaction extensions inside any-db itself.