Remove use of httpbin

This is done in order to prevent confusion. We are trying to stop using
httpbin.org for our tests. Even when the tests for the requests
instrumentation do not actually perform any request to httpbin.org,
because the test requests are being mocked with httpretty, having the
string httpbin.org in the tests can cause confusion and make the reader
think the tests are actually using httpbin.org.

Fixes open-telemetry#1844

Author: ocelotl

instrumentation/opentelemetry-instrumentation-requests/tests/test_requests_integration.py

@@ -63,7 +63,7 @@ class RequestsIntegrationTestBase(abc.ABC):
     # pylint: disable=no-member
     # pylint: disable=too-many-public-methods
 
-    URL = "http://httpbin.org/status/200"
+    URL = "http://mock/status/200"
 
     # pylint: disable=invalid-name
     def setUp(self):
@@ -152,7 +152,7 @@ def response_hook(span, request_obj, response):
         self.assertEqual(span.attributes["response_hook_attr"], "value")
 
     def test_excluded_urls_explicit(self):
-        url_404 = "http://httpbin.org/status/404"
+        url_404 = "http://mock/status/404"
         httpretty.register_uri(
             httpretty.GET,
             url_404,
@@ -194,7 +194,7 @@ def name_callback(method, url):
         self.assertEqual(span.name, "HTTP GET")
 
     def test_not_foundbasic(self):
-        url_404 = "http://httpbin.org/status/404"
+        url_404 = "http://mock/status/404"
         httpretty.register_uri(
             httpretty.GET,
             url_404,
@@ -460,7 +460,7 @@ def perform_request(url: str, session: requests.Session = None):
         return session.get(url)
 
     def test_credential_removal(self):
-        new_url = "http://username:password@httpbin.org/status/200"
+        new_url = "http://username:password@mock/status/200"
         self.perform_request(new_url)
         span = self.assert_span()