check for publisher rules update once a day

[mrose17]

cf., brave/ledger-client#13

[alexwykoff]

How would QA go about testing this?

[mrose17]

in ledger-state*.json, the rulesStamp gives the timestamp of the next update.

because the rules might not change within a 24h period, it probably makes more sense to look for the stamp to update by approximately 86,400,000 after 24h.

yes, not a very easy thing to do, but there you have it.

alternately, you could modify the value to be in the past and set ruleset to [] run the browser for a couple of minutes and see if both rulesStamp and rules change (in a good way!)