Changes to talk (edit) aren't saved

[martian-a]

To reproduce:

1. I find an existing talk and click on the edit option
2. I change the title, speaker and/or description data
3. I click on the "Update talk" button
4. I am redirected to the "show" view of that talk which includes a message telling me that the talk has been successfully updated.

Expected result:

• to see the that changes that I've just made have been saved, as evidenced by the data in the view.

Actual result:

• no changes has been saved. The data is the same as it was before I edited it.

[kevinprince]

Fixed.

[martian-a]

Thanks.