Update ci.yml

Author: Crazy-Rich-Meghan

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, ubuntu-latest]
+        os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@master
         with: