add agola build config

.agola/config.jsonnet

@@ -0,0 +1,38 @@
+local node_runtime(version, arch) = {
+  arch: arch,
+  containers: [
+    {
+      image: 'node:' + version,
+    },
+  ],
+};
+
+local task_build(version, arch) = {
+  name: 'build - node ' + version + ' ' + arch,
+  runtime: node_runtime(version, arch),
+  environment: {},
+  steps: [
+    { type: 'run', command: 'env' },
+    { type: 'clone' },
+    { type: 'restore_cache', keys: ['cache-node'+version+'-sum-{{ md5sum "package.json" }}', 'cache-node'+version+'-date-'], dest_dir: './node_modules' },
+    { type: 'run', command: 'npm install' },
+    { type: 'run', command: 'npm run build' },
+    { type: 'save_cache', key: 'cache-node'+version+'-sum-{{ md5sum "package.json" }}', contents: [{ source_dir: './node_modules' }] },
+    { type: 'save_cache', key: 'cache-node'+version+'-date-{{ year }}-{{ month }}-{{ day }}', contents: [{ source_dir: './node_modules' }] },
+  ],
+};
+
+{
+  runs: [
+    {
+      name: 'agola web build/test',
+      tasks: std.flattenArrays([
+        [
+          task_build(version, arch),
+        ]
+        for version in ['11', '12']
+        for arch in ['amd64']
+      ]) 
+    },
+  ],
+}