Update ci.yml

Author: ViralBShah

.github/workflows/ci.yml

@@ -15,9 +15,8 @@ jobs:
       fail-fast: false
       matrix:
         julia-version:
-          - "1.3"
+          - "1.6"
           - "1"
-          - "nightly"
         os:
           - ubuntu-latest
           - macos-latest