v0.3.0

Main changes

• Exports the selected dataframe in a spark-compatible formated. coercing the precision of datetime columns (#2)
• Treats date columns with the appropriate backend (#3)
• Columns that define partitions now can receive aliases in the query (#4)
• The file format for partitioned tables in both S3 and FS storages don't need a final dash - before the extension (#5)
• Schema data types for columns were changes: integer -> int and number-> float