Update release notes for 0.3.2
# Release Notes
+## Changes in Transact 0.3.2
+
+### libtransact Updates
+
+* Fix an issue in `state::merkle::MerkleRadixTree` where an empty set of state
+ changes would produce an empty state id. This has been updated to return the
+ current state root hash.
+* Fix two issues in the `SerialScheduler` with call ordering of `cancel` and
+ `finalize`. These methods can be called in either order.
+
## Changes in Transact 0.3.1
### Highlights
