Fix tests.

Author: ioquatix

test/async/dns/resolver.rb

@@ -13,7 +13,7 @@
 	let(:resolver) {Async::DNS::Resolver.default}
 
 	it "should result in non-existent domain" do
-		response = resolver.query("foobar.example.com", Resolv::DNS::Resource::IN::A)
+		response = resolver.query("example.invalid", Resolv::DNS::Resource::IN::A)
 
 		expect(response.rcode).to be == Resolv::DNS::RCode::NXDomain
 	end

test/async/dns/server.rb

@@ -38,7 +38,7 @@ def make_server(endpoint)
 		end
 
 		it "can resolve non-existent domain name" do
-			response = resolver.query("foobar.example.com")
+			response = resolver.query("example.invalid")
 
 			expect(response).to have_attributes(
 				qr: be == 1,