fix: replace weight calculation with a rounded ceil

Author: samc

lib/utils/DecisionUtil.js

@@ -1013,7 +1013,7 @@ let DecisionUtil = {
   ) {
     // normalise the weights of all the shortlisted campaigns
     shortlistedCampaigns.forEach(campaign => {
-      campaign.weight = Math.floor(100 / shortlistedCampaigns.length);
+      campaign.weight = Math.ceil((100 / shortlistedCampaigns.length) * 10) / 10;
     });
 
     // re-distribute the traffic for each camapign