Test change resolution scope with absolute reference

[matt-allan]

Hello,

This PR adds a test for a scenario outlined in 7.2.2 of the specification.

{
    "id": "http://x.y.z/rootschema.json#",
    "schema1": {
        "id": "#foo"
    },
    "schema2": {
        "id": "otherschema.json",
        "nested": {
            "id": "#bar"
        },
        "alsonested": {
            "id": "t/inner.json#a"
        }
    },
    "schema3": {
        "id": "some://where.else/completely#"
    }
}

Subschemas at the following URI-encoded JSON Pointer [json‑pointer]s (starting from the root schema) define the following resolution scopes:

#/schema3
some://where.else/completely#

With the current test suite, it's possible to write a validator that does not check if the reference is absolute and always appends. This test should ensure that you try to resolve:

http://localhost:1234/folder/folderInteger.json

...instead of :

http://localhost:1234/http://localhost:1234/folder/folderInteger.json

[epoberezkin]

@Relequestual this is another similar one to PR #160 (yet different) that I think we should merge.

[Relequestual]

Given section 7.2.2 isn't even there any more, I'll opt to close this in favour of keeping track of #160 . Thanks all the ame @yuloh =]

[epoberezkin]

@Relequestual I think we should still have this test, even though the reference isn't in the spec anymore, this test should still pass - #160 is similar but not the same. But it should be in both draft-04 and in in draft-06, so this PR needs changes. @handrews, can you review this one as well when you have a moment?