Implement a way to download DB exports

[carlosms]

This issue is to implement a temporary (and very basic) way to use the web interface to:

• export the data to a SQLite DB
• download that file

[bzz]

@carlosms do you think

1. It may be worth documenting existence of the /exports somewhere as well, with link to schema, etc?

   So the users would be able to learn about it without deep-dive into the app code?

2. Also, as un-authorized user, I was able to access /exports page

[dpordomingo]

just to clarify it... 2 is not a security problem but a UX thing (because no Requester can do nothing there)

[ricardobaeta]

I'm here to help.

[carlosms]

@bzz said:

@carlosms do you think

It may be worth documenting existence of the /exports somewhere as well, with link to schema, etc?
So the users would be able to learn about it without deep-dive into the app code?

Yes, I'll add it to the readme. But this route should probably have a link from somewhere in the app.
Can you please clarify what do you with link to schema? Do you want to have a new file with the schema for the assignments table and link to it from the readme?

Also, as un-authorized user, I was able to access /exports page

As @dpordomingo said, that is not a security problem, you can access the route but you won't be able to do or see anything. Improving this is part of #47, and I guess we'll show an empty page with a message to let you know you are not authorized.