v0.2.1

What's Changed

• Added VirtualDataset class; move towards Pangeo support by @jkrasting in #15
• Fixed typo in chunk_freq search logic by @jkrasting in #16
• Added diag.open() method and updated basic.ipynb by @jkrasting in #17
• Updated enso.ipynb example notebook by @jkrasting in #18

Full Changelog: v0.2.0...v0.2.1