Ability for users to publish multiple medcial, travel and intersection data

[theTechie]

As of now, the API seems to be designed so that the medmap, travel and intersection data can only be published one by a user.

As discussed 26/4,

• we will be removing this restriction for the beta release
• API would just replace the old data with the new one's published

But, we will need to consider this case,

• should we maintain multiple versions of the data in the backend for every user?
• or there should be only one data point per user?

Also, how will the case of "submitting data for others" work?

@sanjanamoha @codeJRV @Aakashv6