Bug Fixes
* ALTER DATABASE ddl not supported (https://github.com/GoogleCloudPlatform/cloud-spanner-emulator/issues/27)
* Include varchar limit for varchar types in the spanner\type column of information_schema.columns and information_schema.index_columns tables.
* Fix foreign key transaction restriction for the transaction with multiple flush.
* Fix foreign key action effector for unordered referencing FK.
New Feature
* Support proto and enum types in cloud spanner emulator\.
* Enable support for JSON converter functions and LAX converters in cloud spanner emulator\
* Support ALTER DATABASE DDL as a no-op
* Support Sequence in PostgreSQL.
* Return unsupported error for upsert queries
* Add builtin PostgreSQL TVFs
* Enable Foreign Key Delete Cascade Action.
* Adding ML_PREDICT_ROW function
* Enable INSERT OR IGNORE and INSERT OR UPDATE
* Adding ML.PREDICT function.
* Support Directed Reads feature
Dependencies
* upgrade distroless docker build
* upgrade go language dependency