Use href from iframe media response

Turns out, href exists in the mediaResponse query. I can use that
instead of fetching that separately.

spec/classes/iframe_media_resolver_spec.cr

@@ -1,27 +0,0 @@
-require "../spec_helper"
-
-include Nodes
-
-describe IFrameMediaResolver do
-  around_each do |example|
-    original_client = IFrameMediaResolver.http_client
-    IFrameMediaResolver.http_client = FakeMediumClient
-    example.run
-    IFrameMediaResolver.http_client = original_client
-  end
-
-  it "returns a url of the embedded page" do
-    iframe = PostResponse::IFrame.from_json <<-JSON
-      {
-        "mediaResource": {
-          "id": "d4515fff7ecd02786e75fc8997c94bbf"
-        }
-      }
-    JSON
-    resolver = IFrameMediaResolver.new(iframe: iframe)
-
-    result = resolver.fetch_href
-
-    result.should eq("https://example.com")
-  end
-end

spec/classes/paragraph_converter_spec.cr

@@ -3,13 +3,6 @@ require "../spec_helper"
 include Nodes
 
 describe ParagraphConverter do
-  around_each do |example|
-    original_client = IFrameMediaResolver.http_client
-    IFrameMediaResolver.http_client = FakeMediumClient
-    example.run
-    IFrameMediaResolver.http_client = original_client
-  end
-
   it "converts a simple structure with no markups" do
     paragraphs = Array(PostResponse::Paragraph).from_json <<-JSON
       [
@@ -289,7 +282,7 @@ describe ParagraphConverter do
           "href": null,
           "iframe": {
             "mediaResource": {
-              "id": "7c6231d165bf9fc1853f259a7b55bd14"
+              "href": "https://example.com"
             }
           },
           "layout": null,

spec/support/fake_medium_client.cr

@@ -1,9 +0,0 @@
-class FakeMediumClient < MediumClient
-  def self.media_data(media_id : String) : MediaResponse::Root
-    MediaResponse::Root.from_json(
-      <<-JSON
-        {"payload": {"value": {"href": "https://example.com"}}}
-      JSON
-    )
-  end
-end