Wrote WebClientHttpRoutingFilterTests. Relates to GH-73

[NadChel]

I ran a coverage tool and noticed that one of the key GlobalFilers, WebClientHttpRoutingFilter, has a coverage of zero (at least, excluding integration tests). I bumped it up to 100%

Also wrote a missing Javadoc

Important note. I want you to delay the merge until we figure out how to assert on ClientResponse's body. The last test, filter_ifNotRouted_ifSchemeHttps_receivedResponseStoredAsAttribute(), was supposed to have this assertion as well

    StepVerifier.create(storedClientResponse.bodyToMono(String.class))
        .expectNext(responseBody)
        .verifyComplete();

However, the body mono completes immediately so the assertion fails. I tried to pinpoint it on my own for a while, but then remembered that I no longer work on some pet project of mine and can continue solving that puzzle together with the Spring Cloud community. Maybe, it's not a puzzle at all

[spencergibb]

Yeah, there's a reason it's not tested. I'm likely going to deprecate it for removal.

[NadChel]

Do you mean deprecating WebClientHttpRoutingFilter or ClientResponse?

[spencergibb]

WebClientHttpRoutingFilter

[NadChel]

Well, but shouldn't it be covered while it's still part of the framework?