fixed cadence bug I introduced in the last release

I also attached the getValidInsertionPoints function to the zones API

Author: pilgreen

index.js

@@ -23,8 +23,9 @@ function distributeZones(locker) {
       resolve("zones-loaded")
     });
 
-    // Set up the communication bridge
+    // Add the communication bridge and vip method to the zones API
     locker.getYozonsLocker("zones").changes = zones.changes;
+    locker.getYozonsLocker("zones").getValidInsertionPoints = zones.getValidInsertionPoints;
   });
 }
 

lib/zones.js

@@ -217,10 +217,11 @@ export function getValidInsertionPoints() {
 
 export function distribute(tick = 4) {
   const vips = getValidInsertionPoints();
+  const cadence = tick;
 
   map.forEach(zone => {
     zone.vip = vips[tick];
-    tick += tick;
+    tick += cadence;
   });
 }