run git fetch on CI (#170)

Author: shashi

.github/workflows/ci.yml

@@ -13,6 +13,8 @@ jobs:
       - uses: actions/checkout@v2
         with:
           fetch-depth: 0
+      - run: |
+          git fetch origin master:master
       - uses: julia-actions/setup-julia@v1
         with:
           version: 1