Use install file for 4.7.0

Add something like the following as taxonomy_assoc.install for 4.7.0.

/**
 * Implementation of hook_install()
 */
function taxonomy_assoc_install()
	{
	global $db_type;
	switch ($db_type)
		{
		case 'mysql':
		case 'mysqli':
			db_query("create table taxonomy_assoc (
				txnid int(10) unsigned not null auto_increment,
				nid int(10) unsigned not null default 0,
				tid int(10) unsigned not null default 0,
				primary key (txnid),
				key txn_nid (nid),
				key txn_tid (tid)
				) type=myisam;");
			break;
		}
	drupal_set_message(t('All tables required by the bookreview module have been created.'));
	}

The actual table should eventually be converted to just nid and tid as dual primary keys.