Run tests on Windows with Python 3.

.github/workflows/ci.yml

@@ -18,6 +18,7 @@ jobs:
       fail-fast: false
       matrix:
         os:
+          - windows-latest
           - macos-latest
           - ubuntu-latest
         python-version:
@@ -26,11 +27,6 @@ jobs:
           - 3.7
           - 3.8
           - 3.9
-        include:
-          # For now we're only doing Windows on 2.7, will be fixed in
-          # https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3701
-          - os: windows-latest
-            python-version: 2.7
 
     steps:
       # See https://github.com/actions/checkout. A fetch-depth of 0