workaround ci msrv issue

Author: robjtede

.github/workflows/ci.yml

@@ -77,6 +77,11 @@ jobs:
         uses: actions-rs/cargo@v1
         with: { command: generate-lockfile }
 
+      - name: workaround MSRV issues
+        if: matrix.version != 'stable'
+        run: |
+          cargo update -p=time --precise=0.3.13
+
       - name: check lib
         if: >
           matrix.target.os != 'ubuntu-latest'