Update codecov-action to v2 and make it possible to keep it up-to-date with dependabot (#1181)

* Update codecov-action to v2

* Add github-actions to dependabot

.github/dependabot.yml

@@ -6,3 +6,10 @@ updates:
     interval: daily
     time: "20:00"
   open-pull-requests-limit: 10
+
+- package-ecosystem: "github-actions"
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "20:00"
+  open-pull-requests-limit: 10

.github/workflows/coverage.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Generate code coverage
         run: cargo llvm-cov --all-features --workspace --lcov --output-path lcov.info
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v1
+        uses: codecov/codecov-action@v2
         with:
           token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos
           files: lcov.info