Fix gemspec: permit ruby version >= 2.
release 0.4.4

* Fix gemspec: permit ruby version >= 2.
Expand file paths in #copy and #new.
Merge pull request #25 from minad/expand_paths

Expand file paths in #copy and #new.
Fix bug: mark cursor list in transaction_mark.
release 0.4.5

* Expand file paths in #copy and #new.
* Fix bug: mark cursor list in transaction_mark.
Expose mdb_env_set_mapsize() as Environment#mapsize=.
Handle MDB_MAP_RESIZED.
Merge pull request #27 from minad/mapsize

Mapsize