Allow insertion of multiple objects
Version bump to v1.3.3
Fixed hook error on insert, v1.3.4
Updated validation library
Version bump to v1.3.5
Improve error messages for validation of missing values
Fix return values for Model.insert
Version bump to v1.3.6
Rewrote insertion logic

Improves performance, supports transformations and renames, and includes
improved support for multiple entry insertions.
Documented preprocessing steps in README
Added more tests for Model, focusing on DB CRUD
Version bump to v1.3.7
More improvements to rename functionality, v1.3.8
Fix typo (renames -> rename)
Fixed rename handling in Instance (missed because of previous typo)
Version bump to v1.3.9