GH Actions: Codecov (#366)

* Add codecov gh action

* Skip integration tests

.github/workflows/codecov.yml

@@ -0,0 +1,45 @@
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+
+name: Codecov
+
+jobs:
+  test:
+    name: Test
+    env:
+      RUSTFLAGS: -C instrument-coverage
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+      - name: Checkout submodules
+        run: git submodule update --init --recursive
+      - uses: actions/setup-go@v3 # we need go to build go-waku
+        with:
+          go-version: '1.19'
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+          components: llvm-tools-preview
+      - uses: actions-rs/cargo@v1
+        continue-on-error: true
+      - run: |
+          cargo install grcov;
+          cargo test --no-default-features --features waku -- --skip ten_nodes_happy --skip two_nodes_happy --skip ten_nodes_one_down
+          cargo test --no-default-features --features libp2p -- --skip ten_nodes_happy --skip two_nodes_happy --skip ten_nodes_one_down
+          mkdir /tmp/cov;
+          grcov . --binary-path ./target/debug/ -s . -t lcov --branch --ignore-not-existing --ignore '../*' --ignore "/*" -o /tmp/cov/tests.lcov;
+      - uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          directory: /tmp/cov/
+          name: nomos-node-codecov
+          fail_ci_if_error: true
+
+