Guide to Updating Hex.pm for Ecto 3.0

This article by Wojtek Mach focuses on the process of updating Hex.pm to Ecto 3.0. It explains the steps required to update dependencies, adjust configurations, and handle new constraints introduced in Ecto 3.0. The guide highlights specific code changes and commits made during the update, dealing with new project dependencies like `ecto_sql`, `DBConnection` changes, and stricter date/time precision requirements in Ecto 3.0. Additionally, it covers how to resolve deprecation warnings and minor specific issues for Hex.pm. The author emphasizes the improved maturity of Ecto that made the upgrade process smoother compared to previous updates.