iadrich

`load_data` crashes when records are not homogeneous. We can simply reshape the batch before issuing the insert statement to fix it here: https://github.com/173TECH/sayn/blob/d1cf36b92fad6a1798b57ad80abb22e8386e0e86/sayn/database/__init__.py#L298

**Database** Currently, database errors raise exceptions and so the message is just the error produced by the driver. We can improve this in known cases like autosql and copy tasks...

When load_data is called with no ddl information, table structure is determined by the first row. If this row contains None values the type can't be determined and table creation...

```python with self.step('Execute SQL'): return self.failed() ``` With this code, the step is tracked as successful. We need a better way to fail a step when using the context.

At the moment we're relying on sqlalchemy data type translations when the columns in copy tasks are not specified, but it doesn't necessarily cover all cases. So the proposed actions...