Unable to perform migration using GENERATE_UUID()

[tomopy03]

Expected Behavior

Creating a migration file using GENERATE_UUID() should be successful. The use of GENERATE_UUID() should be available. https://cloud.google.com/spanner/docs/primary-key-default-value#universally_unique_identifier_uuid

Current Behavior

Fails with errors like:

Error command: up, version: 1.6.0
        failed to parse DDL/DML statements: 000001.sql:2: got "(" while expecting ")", 000001.sql:1.0: unknown DML statement

Steps to Reproduce

1. Create the database using wrench:

   wrench create --directory ./schema

2. Create a new migration file:

   
   wrench migrate create --directory ./schema

cat ./schema/migrations/000001.sql

CREATE TABLE test ( test_id STRING(36) NOT NULL DEFAULT (GENERATE_UUID()) );

3. Run migration:

wrench migrate up --directory ./schema

## Context (Environment)

* wrench version: 1.6.0

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[tomopy03]

Solved to v1.7.0. Thank you for updated!