[#57378292] Fetcher implementation
[#57378292] Fetcher specs
[#57378292] Refactor specs and silence logger in tests
Asynchronous fetching with in memory persistence
Queue specs
Specs for spawner
Included spawner
Spawner specs
Spawn fetching threads when starting server
Unnecessary dependency
Ensure that fetcher is removed from queue after processing
Responding to PR concerns
Clean up pull request
Changed fetch method to perform
Merge remote-tracking branch 'dawid/tech-doctors/be-faster-on-cache-misses-57378292' into merge-with-dawid

Conflicts:
	Gemfile
	Gemfile.lock
	spec/spec_helper.rb
	yarp.rb
	yarp/app.rb
Fixed bug
Added S3 to the list of cachiers
added logging
moved to rainbows the starting of additional threads
Added s3 to the example env file