Add an upload token for Codecov + add badge (ad-freiburg#867)

This avoids spurious failures of the coverage upload due to Github's rate limit for Codecov's public default token. Also add a badge at the top of the README and make the names of the (now four) badges consistent.

.github/workflows/native-build.yml

@@ -113,6 +113,12 @@ jobs:
       uses: codecov/codecov-action@v3
       with:
         file: ${{github.workspace}}/build/test/coverage.lcov
+        # Note: technically, a `token` is not required for codecov.io when
+        # uploading from a public repository, but specifying it avoids the
+        # nasty spurious failures due to Github's rate limit for codecov's
+        # public default token.
+        token: ${{ secrets.CODECOV_TOKEN }}
+        fail_ci_if_error: true
 
     - name: E2E
       run: ${{github.workspace}}/e2e/e2e.sh

README.md

@@ -1,8 +1,9 @@
 # QLever
 
-[![Build Status via Docker](https://github.com/ad-freiburg/QLever/actions/workflows/docker.yml/badge.svg)](https://github.com/ad-freiburg/QLever/actions/workflows/docker.yml)
+[![Docker build](https://github.com/ad-freiburg/QLever/actions/workflows/docker-build.yml/badge.svg)](https://github.com/ad-freiburg/QLever/actions/workflows/docker-build.yml)
 [![Native build](https://github.com/ad-freiburg/qlever/actions/workflows/native-build.yml/badge.svg)](https://github.com/ad-freiburg/qlever/actions/workflows/native-build.yml)
-[![Code Format Check](https://github.com/ad-freiburg/qlever/actions/workflows/format-check.yml/badge.svg)](https://github.com/ad-freiburg/qlever/actions/workflows/format-check.yml)
+[![Format check](https://github.com/ad-freiburg/qlever/actions/workflows/format-check.yml/badge.svg)](https://github.com/ad-freiburg/qlever/actions/workflows/format-check.yml)
+[![Test coverage](https://codecov.io/github/ad-freiburg/qlever/branch/master/graph/badge.svg?token=OHcEh02rW0)](https://codecov.io/github/ad-freiburg/qlever)
 
 QLever (pronounced "Clever") is a SPARQL engine that can efficiently index and query very large knowledge graphs with up to 100 billion triples on a single standard PC or server.
 In particular, QLever is fast for queries that involve large intermediate or final results, which are notoriously hard for engines like Blazegraph or Virtuoso.