Don't use aiohttp==3.7.0

aio-libs/aiohttp#5110 means that https URLs
don't work.  aio-libs/aiohttp#5118 fixes the
issue, and will be included in 3.7.1.

changelog/issue-3767.md

@@ -0,0 +1,5 @@
+audience: users
+level: patch
+reference: issue 3767
+---
+This version adjusts the Python client requirements to avoid `aiohttp==3.7.0`, which has a [serious bug preventing use of HTTPS](https://github.com/aio-libs/aiohttp/issues/5110).

clients/client-py/setup.py

@@ -62,7 +62,8 @@ def run_tests(self):
     raise Exception('This library does not support Python 3 versions below 3.5')
 elif sys.version_info[:2] >= (3, 5):
     install_requires.extend([
-        'aiohttp>=2.0.0',
+        # 3.7.0 is broken - see https://github.com/taskcluster/taskcluster/issues/3767
+        'aiohttp>=2.0.0,!=3.7.0',
         'async_timeout>=2.0.0',
     ])
 

clients/client-py/tox.ini

@@ -17,5 +17,6 @@ extras = test
 usedevelop = true
 
 commands =
+    pip freeze
     {envbindir}/py.test --cov-config .coveragerc --cov=taskcluster --cov-report term-missing -v {env:IG:} {env:EX1:} {env:EX2:}
     ./lint.sh --python "{envpython}" --flake8 "{envbindir}/flake8"