Operations: archiving the testnet before olympia upgrade

[mochet]

Currently, we are about to upgrade in the next few days to giza. Sometime soon after that we will be upgrading to olympia and all of the current forum content as well as proposals and historical council information will be reset.

The current plan from JSG appears to indicate that olympia will really form the basis of a lot of mainnet things:
Joystream/joystream#3012

Therefore it is important (I think) to make a good backup prior to olympia being launched and that its contents are recorded somewhere public.