refactor: moved http.Client to model.RequestContext

Signed-off-by: SoXX <soxx@fenpa.ws>

pkg/e621/endpoints/tag_test.go

@@ -31,14 +31,14 @@ func TestGetTag(t *testing.T) {
 	httpmock.RegisterResponder("GET", "https://e621.net/tags/165165.json", jsonResponser)
 
 	requestContext := model.RequestContext{
+		Client:    http.Client{},
 		Host:      "https://e621.net",
 		UserAgent: "Go-e621-SDK (@username)",
 		Username:  "memo",
 		APIKey:    "123456",
 	}
 
-	client := http.Client{}
-	tag, err := GetTag(client, requestContext, "165165")
+	tag, err := GetTag(requestContext, "165165")
 	if err != nil {
 		t.Error(err)
 		return