Update ci.yml

Author: hjerpbakk

.github/workflows/ci.yml

@@ -7,7 +7,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macOS-latest, ubuntu-latest, windows-latest]
+        #os: [macOS-latest, ubuntu-latest, windows-latest]
+        os: [ubuntu-latest]
     steps:
     - uses: actions/checkout@v1
     - name: Build and test container