migrate primary key changes

[raviteja nandula]

Hi All,

I have created a model with primary key, later i have removed the primary key and used default `id` as primary key

When i tried to migrate it is throwing error with multiple primary keys defined

Before running migrate i have executed on MySQL command interface

    "ALTER TABLE `table_name` DROP PRIMARY KEY;"

After this i re run the migrate. It executed perfectly.

Thanks

Ravi Teja N