v0.5.0

• Restructured class hierarchy to have a more generic DataAsset parent that maintains expectation logic separate from the tabular organization of Dataset expectations
• Added new FileDataAsset and associated expectations (#416 thanks @anhollis)
• Added support for date/datetime type columns in some SQLAlchemy expectations (#413)
• Added support for a multicolumn expectation, expect multicolumn values to be unique (#408)
• Optimization: You can now disable partial_unexpected_counts by setting the partial_unexpected_count value to 0 in the result_format argument, and we do not compute it when it would not be returned. (#431, thanks @eugmandel)
• Fix: Correct error in unexpected_percent computations for sqlalchemy when unexpected values exceed limit (#424)
• Fix: Pass meta object to expectation result (#415, thanks @jseeman)
• Add support for multicolumn expectations, with expect_multicolumn_values_to_be_unique as an example (#406)
• Add dataset class to from_pandas to simplify using custom datasets (#404, thanks @jtilly)
• Add schema support for sqlalchemy data context (#410, thanks @rahulj51)
• Minor documentation, warning, and testing improvements (thanks @zdog).