Version 0.3.6

This is a maintenance version, to adapt to the new CDS system for ERA5. No new features are added.

What's Changed

• readme: install tests/requirements.txt while building from source by @yunjunz in #39
• update to the official new CDS by @yunjunz and @yuankailiu in #44

Full Changelog: v0.3.5...v0.3.6