Use double instead of float for MySQL compatability

[ryanmitchell]

Change the form id migration to use double as float isn't consistent in MySQL

[clementmas]

FYI, Laravel's double() function doesn't accept a precision parameter:

/**
 * Create a new double column on the table.
 *
 * @param  string  $column
 * @return \Illuminate\Database\Schema\ColumnDefinition
 */
public function double($column)
{
    return $this->addColumn('double', $column);
}

So it will use the default MySQL DOUBLE precision which is around 15 digits, which should still work I think.

[ryanmitchell]

My mistake, it was meant to be decimal not double