Made a few changes to schema for MySQL grammar

... with foreign keys where the data length did not match. Here it is always explicitly set.

Also added a fluen attribute to timestamp type. The attribute '$column->auto()' makes the column auto updatable.
Laravel takes care of this value when updating the db, but sometimes db updates are manual and the timestamp value does not change or needs to be manually done.
It is just safer to make it auto for most use cases.