Update windows testing for CI

Author: warmwaffles

.github/workflows/ci.yml

@@ -47,16 +47,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: ["ubuntu-20.04"]
+        os: ["ubuntu-20.04", "windows-2019"]
         elixir: ["1.14", "1.13", "1.12", "1.11"]
         otp: ["25", 24", "23"]
-        include:
-          - os: windows-2019
-            elixir: "1.13"
-            otp: "24"
-          - os: windows-2019
-            elixir: "1.12"
-            otp: "24"
+        exclude:
+          - elixir: "1.12"
+            otp: "25"
+          - elixir: "1.11"
+            otp: "25"
     steps:
       - uses: actions/checkout@v2
       - uses: erlef/setup-beam@v1