Check for undefined values when making filled arrays

lib/make/arrays.js

@@ -8,7 +8,10 @@ make.arrays = {
     let size = limit || random.number(make.number.tiny()) + 1
 
     for (let i = 0; i < size; i++) {
-      array.push(random.pick(fn))
+      let value = random.pick(fn)
+      if (value !== undefined) {
+        array.push(value)
+      }
     }
 
     return array