Announcing release v3.1.0 of Oppia!

[Akshay Anand]

Hi Oppia Devs,

We are happy to announce the release of v3.1.0 of Oppia.

The main updates in this release are the completion of migration of user accounts to Firebase (Python 3 migration), regeneration of missing exploration stats models in production, general bug fixes, UI improvements and migration of AngularJS services to Angular.

Please welcome Aasif Faizal, Benjamin Beeshma, Eesha Arif, Naman Kalra, Nisarg Chaudhari, Nitanshu Lokhande, Pawan Rai, Pawel Borkar, Sanjana Konte, and Tanishq Gupta for whom this release marks their first contribution to Oppia!

Thanks to Aditya Dubey, Aishwary Saxena, Akshay Anand, Anshul Hudda, Apurv Botle, Archi Aggarwal, Arkadyuti Bandyopadhyay, Aryaman Gupta, Ashutosh Chauhan, Brian Rodriguez, Chris, Eric Lou, Farees Hussain, Harsh Khilawala, Hasitha Kaushan, Hitesh Tomar, Kevin Thomas, Kishan Kumar, Md Shahbaz Alam, Nikhil, Nithesh N. Hariharan, Praneeth, Parul Priyedarshani, Prayush Dawda, Radesh, Rijuta Singh, Rohit Katlaa, Sandeep Dubey, Sean Lip, Siddharth Batra, Srijan Reddy, Subodh Verma, Vojtěch Jelínek, Y. Budhachandra Singh, Jacque Li, Jim Zhan, Krishna Rao, Mridul Setia, and Sajna, our returning contributors who made this release possible.

FInally, I'd like to thank Preethi, Chris, Sandeep, Jim Zhan, Prayush, Mridul, Harsh and Nithesh for their help with pre-release testing, bug-fixing and QA, as well as Chris for leading the QA team for this release.

Thanks,
Akshay (on behalf of the release team)