Modernize code

[ioquatix]

Due to recent changes in Ruby (support for fiber_interrupt), the after block can raise an exception:

describe Async::HTTP::Faraday::Adapter with a local http server with a no content response it properly handles no content responses test/async/http/faraday/adapter.rb:132
	expect "" to
		be == ""
			✓ assertion passed test/async/http/faraday/adapter.rb:133
	⚠ IOError: stream closed in another thread
describe Async::HTTP::Faraday::Adapter with a local http server with a slow response it client can get resource test/async/http/faraday/adapter.rb:145
	expect "Hello World" to
		be == "Hello World"
			✓ assertion passed test/async/http/faraday/adapter.rb:146
	⚠ IOError: stream closed in another thread
describe Async::HTTP::Faraday::Adapter with a local http server with a slow response it raises an exception if request times out test/async/http/faraday/adapter.rb:149
	expect #<Proc:0x00007f107d393b38 test/async/http/faraday/adapter.rb:150> to
		raise exception Faraday::TimeoutError
			✓ raised test/async/http/faraday/adapter.rb:152
	⚠ IOError: stream closed in another thread
describe Async::HTTP::Faraday::Adapter with a local http server with a config block it invokes the config block test/async/http/faraday/adapter.rb:192
	expect true to
		be == true
			✓ assertion passed test/async/http/faraday/adapter.rb:203
	⚠ IOError: stream closed in another thread

Types of Changes

• Bug fix.
• Maintenance.

Contribution

• I added tests for my changes.
• I tested my changes locally.
• I agree to the Developer's Certificate of Origin 1.1.

[ioquatix]

For reference, it was found when fixing this: socketry/async-http-faraday#52