drop unsupported pythons for now

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2

setup.py

@@ -19,7 +19,7 @@ setup(name="magic-wormhole-transit-relay",
       package_data={"wormhole_transit_relay": ["db-schemas/*.sql"]},
       install_requires=[
           "twisted >= 21.2.0",
-          "autobahn",
+          "autobahn >= 21.3.1",
       ],
       extras_require={
           ':sys_platform=="win32"': ["pypiwin32"],