Migrate data source

[iorrah]

We currently fetch data from an Ecosia endpoint.

The idea is to migrate to some of the following options:

• Pinterest API: according to the official documentation, it is possible to fetch data an specific endpoint upon a authorisation (OAUTH) by integrating third-party applications with the Pinterest SDK;
• Ember Firebase: another option would be install this official adaptor in the app which would allow us to integrate the app with Firebase and even to customise the properties presented in the response objects. In this scenario, a good idea would be upload the images to ImgUR and use the resulting image URL as hoturl.