* add youtube oembed endpoint
* add check for oembed endpoint
* change unless for a more readable if
* clear blank lines
* endpoint via https
* Fix string literal in condition
* use cache for endpoints
* use cache for endpoints
* clean up and adding check
* clean up and remove redundant return
* add html check
* add false to return
* use double quotes
* use double quotes
* Clean up
* Fix undefined method error in sidekiq
Body can be not nil but still be empty, which causes a
`NoMethodError: undefined method `[]' for nil:NilClass` further in the
code. This checks for an empty body to avoid the issue.
* Fix codeclimate issue
* No need to re-require sidekiq plugins, they are required via Gemfile
* Add derailed_benchmarks tool, no need to require TTY gems in Gemfile
* Replace ruby-oembed with FetchOEmbedService
Reduce startup by 45382 allocated objects
* Remove preloaded JSON-LD in favour of caching HTTP responses
Reduce boot RAM by about 6 MiB
* Fix tests
* Fix test suite by stubbing out JSON-LD contexts
* Do not default the format in ProviderDiscovery
The format should be determined when discovering, as it is in the current
implementation, and it is a flaw if it is not determined.
* Spec ProviderDiscovery
Eugen Rochko