Support for setting multiples keys

[gperdomor]

Is your feature request related to a problem? Please describe.
Currently Keyv expose methods for getting multiple keys using the get method and passing an array of keys as argument, sadly this is not possible in set method...

Describe the solution you'd like
Expose a multi set keys method in Keyv :D

[jaredwray]

@gperdomor - thanks so much and I am going to look at this in the future (next 90 days). If it gets a ton of upvotes we will consider it.