Update to set higher priority caches when determined from lower priority key for single key access

Author: Scott Taylor

Diff for: lib/multi_caching.js

@@ -129,6 +129,9 @@ var multiCaching = function(caches, options) {
                     }
                 } else if (_isCacheableValue(result)) {
                     // break out of async loop.
+                    for (let j = 0; j < i; i++) {
+                      caches[j].store.set(keys, result);
+                    }
                     return cb(err, result, i);
                 }