Verify added and modified servers in CI (github#41)

* Verify added servers in CI.

* Fix typo.

* Cat the catalog for better visibility.

* Add setup stuff.

* Remove buildx.

Author: cmrigney

.github/workflows/ci.yaml

@@ -0,0 +1,43 @@
+on:
+  pull_request:
+
+jobs:
+  validate-servers:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # Needed for diffing
+      
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          cache-dependency-path: go.sum
+          go-version-file: go.mod
+      
+      - name: Install Task
+        uses: arduino/setup-task@v2
+        with:
+          version: 3.x
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      
+      - name: Get changed servers
+        shell: bash
+        run: |
+          git fetch origin ${{ github.event.pull_request.base.ref }}
+          git diff --name-only --diff-filter=AM origin/${{ github.event.pull_request.base.ref }} HEAD | grep "^servers/" > changed-servers.txt || true
+
+      - name: Build and catalog changed servers
+        shell: bash
+        run: |
+          set -eo pipefail
+          while IFS= read -r file; do
+            dir=$(dirname "$file")
+            name=$(basename "$dir")
+            task build -- --tools $name
+            echo "--------------------------------"
+            task catalog -- $name
+            echo "--------------------------------"
+            cat catalogs/$name/catalog.yaml
+            echo "--------------------------------"
+          done < changed-servers.txt