caches.create works without alias

[argaen]

Closes #218

[codecov-io]

Codecov Report

Merging #253 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #253      +/-   ##
==========================================
+ Coverage   99.17%   99.17%   +<.01%     
==========================================
  Files          13       13              
  Lines         844      848       +4     
  Branches       86       88       +2     
==========================================
+ Hits          837      841       +4     
  Misses          7        7

Impacted Files	Coverage Δ
aiocache/factory.py	100% <100%> (ø)	⬆️

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