Ethon: PR feedback

- correct `prepend_instrumentation` comment
- revert `typhoeus?` helper now that only a lone caller remains

lib/new_relic/agent/instrumentation/ethon.rb

@@ -27,8 +27,9 @@
 
   executes do
     if use_prepend?
-      # NOTE: to prevent a string like 'Ethon::Easy' from being converted into
-      #       'Ethon/Easy', a 3rd argument is supplied to `prepend_instrument`
+      # NOTE: by default prepend_instrument will go with the module name that
+      #       precedes 'Prepend' (so 'Easy' and 'Multi'), but we want to use
+      #       'Ethon::Easy' and 'Ethon::Multi' so 3rd argument is supplied
       prepend_instrument Ethon::Easy, NewRelic::Agent::Instrumentation::Ethon::Easy::Prepend, Ethon::Easy.name
       prepend_instrument Ethon::Multi, NewRelic::Agent::Instrumentation::Ethon::Multi::Prepend, Ethon::Multi.name
     else

test/new_relic/http_client_test_cases.rb

@@ -506,7 +506,7 @@ def test_still_records_tt_node_when_request_fails
     # transaction in which the error occurs. That, coupled with the fact that
     # fixing it for old versions of Typhoeus would require large changes to
     # the instrumentation, makes us say 'meh'.
-    skip 'Not tested with Typhoeus < 0.5.4' if typhoeus? && Typhoeus::VERSION < '0.5.4'
+    skip 'Not tested with Typhoeus < 0.5.4' if client_name == 'Typhoeus' && Typhoeus::VERSION < '0.5.4'
 
     evil_server = NewRelic::EvilServer.new
     evil_server.start
@@ -526,10 +526,6 @@ def test_still_records_tt_node_when_request_fails
     evil_server.stop
   end
 
-  def typhoeus?
-    client_name == 'Typhoeus'
-  end
-
   def perform_last_node_assertions
     last_node = find_last_transaction_node()