2.7.0

This release adds support for 'manual' transactions outside a unit of work,
via Atlas::beginTransaction(), commit(), and rollBack() methods.

Also, Row::isEquivalent() now compares booleans as integers, so that a change
from 1 => true or 0 => false (and vice versa) is no longer considered a
difference. This should help reduce "Expected 1 row affected, actual 0" errors
with some databases (notably MySQL).