* Merge [119](https://github.com/brightway-lca/brightway2-io/pull/119): Fix variable error in ecospold1 extraction
* Fix [124: Custom output dir for Excel/CSV export](https://github.com/brightway-lca/brightway2-io/issues/124)
* Fix [131: Issue when importing CSV inventories](https://github.com/brightway-lca/brightway2-io/issues/131)
* Normalize field `reference unit` during unit normalization
* JSON-LD LCIA importer: Can't assume some fields are present