KeyError is thrown when delete!-ing a non-existent key.

[kilminster]

I have LRUCache v1.6.2 installed.

Doing:

using LRUCache

lru=LRU{Int,Int}(maxsize=64)
delete!(lru,5)

results in a ERROR: KeyError: key 5 not found.

This is surprising behaviour since Julia's Dict type allows the equivalent:

d=Dict{Int,Int}()
delete!(d,5)

without throwing any error.