Revert "disabled coverage CI test (#5)"

This reverts commit 1d943ae.

.github/workflows/coverage.yaml

@@ -0,0 +1,43 @@
+name: coverage
+
+on:
+  pull_request:
+    branches: [ "*" ]
+
+jobs:
+  check:
+    name: Rust project
+    runs-on: ubuntu-latest
+
+    defaults:
+      run:
+        working-directory: ./node
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Install stable toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+
+      - name: Run cargo-tarpaulin
+        uses: actions-rs/[email protected]
+        with:
+          version: '0.15.0'
+          args: '--manifest-path node/Cargo.toml -- --test-threads 1'
+        env:
+          RUST_LOG: 'network=trace,sync_blocks=trace,consensus=trace'
+
+      - name: Upload to codecov.io
+        uses: codecov/[email protected]
+        with:
+          token: ${{secrets.CODECOV_TOKEN}}
+
+      - name: Archive code coverage results
+        uses: actions/upload-artifact@v1
+        with:
+          name: code-coverage-report
+          path: cobertura.xml

codecov.yml

@@ -0,0 +1,17 @@
+coverage:
+  range: "10...90"
+  status:
+    # We might gate PRs based on coverage diffs,
+    # but we don't want that for now
+    project:
+      default:
+        informational: true
+    patch:
+      default:
+        informational: true
+
+comment:
+  require_changes: true
+
+github_checks:
+  annotations: false