makes lottery fair (#652)

previous lottery gave first & last members of the chosen array around half the probability of winning vs. other participants since 0.5-1.5 rounds to 1 but only <0.5 rounds to zero.

js/packages/cli/src/fair-launch-cli.ts

@@ -2388,7 +2388,7 @@ program
 
       console.log('Doing lottery for', numWinnersRemaining);
       while (numWinnersRemaining > 0) {
-        const rand = Math.round(Math.random() * (chosen.length - 1));
+        const rand = Math.floor(Math.random() * (chosen.length));
         if (chosen[rand].chosen != true && chosen[rand].eligible) {
           chosen[rand].chosen = true;
           numWinnersRemaining--;