GitHub Actions: add workflow to build network explorer api

.github/workflows/network-explorer-api.yml

@@ -0,0 +1,53 @@
+name: CI for Network Explorer API
+
+on:
+  workflow_dispatch:
+  release:
+    types: [created]
+    
+env:
+  NETWORK: mainnet    
+
+jobs:
+  publish-nym:
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [ubuntu-latest]
+
+    runs-on: ${{ matrix.platform }}
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Check the release tag starts with `nym-explorer-api-`
+        if: startsWith(github.ref, 'refs/tags/nym-explorer-api-') == false && github.event_name != 'workflow_dispatch'
+        uses: actions/github-script@v3
+        with:
+          script: |
+            core.setFailed('Release tag did not start with nym-explorer-api-...')
+
+      - name: Install Rust stable
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+
+      - name: Build all explorer-api
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --manifest-path explorer-api/Cargo.toml --workspace --release
+
+      - name: Upload Artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: my-artifact
+          path: |
+            target/release/explorer-api
+          retention-days: 30
+
+      - name: Upload to release based on tag name
+        uses: softprops/action-gh-release@v1
+        if: github.event_name == 'release'
+        with:
+          files: |
+            target/release/explorer-api

Makefile

@@ -92,6 +92,9 @@ build-wallet:
 build-connect:
 	cargo build --manifest-path nym-connect/Cargo.toml --workspace
 
+build-explorer-api:
+	cargo build --manifest-path explorer-api/Cargo.toml --workspace
+
 build-wasm-client:
 	cargo build --manifest-path clients/webassembly/Cargo.toml --workspace --target wasm32-unknown-unknown