Revert "Use pytest-httpbin and add a test for default User-Agent"

This reverts commit 851e141f3d.

pytest-httpbin doesn't work with nightly. Also it brings in too many
dependencies.

.travis.yml

@@ -8,7 +8,7 @@ python:
   - "3.7"
   - "nightly"
   - "pypy3.6-7.1.1"
-install: pip install -U $DEPS pytest pytest-asyncio pytest-httpbin flaky structlog
+install: pip install -U $DEPS pytest pytest-asyncio flaky structlog
 script: pytest
 env:
   global:

setup.py

@@ -28,7 +28,6 @@ setup(
   tests_require = [
     'pytest',
     'pytest-asyncio',
-    'pytest-httpbin',
     'flaky',
   ],
   entry_points = {

tests/test_regex.py

@@ -4,16 +4,12 @@
 import pytest
 pytestmark = pytest.mark.asyncio
 
-async def test_regex_httpbin_default_user_agent(get_version, httpbin):
+@pytest.mark.skipif(True,
+                    reason='httpbin is overloaded?')
+async def test_regex_httpbin(get_version):
     assert await get_version("example", {
-        "url": httpbin.url + "/get",
-        "regex": r'"User-Agent":\s*"([^"]+)"',
-    }) == "lilydjwg/nvchecker"
-
-async def test_regex_httpbin(get_version, httpbin):
-    assert await get_version("example", {
-        "url": httpbin.url + "/get",
-        "regex": r'"User-Agent":\s*"([^"]+)"',
+        "url": "https://httpbin.org/get",
+        "regex": r'"User-Agent": "(\w+)"',
         "user_agent": "Meow",
     }) == "Meow"