Release 0.3.1
- support returning maps (#149, #186)
- support on-write schema for empty-db (#178)
- add hashmap for transact! (#173)
- cleanup old benchmarks (#181)
- cleanup leftover code (#172)
- fix index selection (#143)
- fix in-memory database existence check (#180)
- improve API docs
- update dependencies
- use java 1.8 for release build (#165)