Add support for PATCH request to ResourceTestRule client when using Grizzly

[danpeter]

Problem:

When using the client from ResourceTestRule with the Grizzly container it is not possible to use PATCH via the custom annotation io.dropwizard.jersey.PATCH. (It seems to work with the in-memory container)
Similar to: #2287

Solution:

Since the builder takes a Consumer<ClientConfig> instead of a property, like in #2287 I choose to set it in the Resource instead of manipulating the builder. This solution is up for discussion.

   protected Resource buildResource() {
   ...
   Consumer<ClientConfig> extendedConfigurator = config -> {
                clientConfigurator.accept(config);
                config.property(HttpUrlConnectorProvider.SET_METHOD_WORKAROUND, true);
            };

Result:

Now possible to use the client and make a PATCH reuqest
client.target(...).request(...).method("PATCH", Entity.text("Patch is working"), String.class)

[nickbabcock]

Looks our CI failed due to an unrelated test. Should be fixed with a commit I just pushed: ff69c2d. Can you rebase off master? 😄

[danpeter]

@nickbabcock I rebased but it is still failing

[joschi]

@danpeter It's still an unrelated flakey test. ☹️

I'll approve and merge this PR.