Tests

Added OAuth v2 and files_upload_v2 samples. #1399

Job	Run time
test (ruby=2.7)	30s
test (ruby=2.7, concurrency=async-websocket)	32s
test (ruby=3.0)	23s
test (ruby=3.1)	24s
test (ruby=3.2)	24s
test (ruby=3.3)	21s
test (ruby=ruby-head)	22s
test (ruby=jruby-head)	1m 49s
coveralls	2s
	4m 47s

Provide feedback