Add basic http server

server/lib/src/ensembles.dart

@@ -0,0 +1,36 @@
+import 'package:aqueduct/aqueduct.dart';
+import 'package:musicus_database/musicus_database.dart';
+
+class EnsemblesController extends ResourceController {
+  final Database db;
+
+  EnsemblesController(this.db);
+
+  @Operation.get()
+  Future<Response> getEnsembles() async {
+    final ensembles = await db.allEnsembles().get();
+    return Response.ok(ensembles);
+  }
+
+  @Operation.get('id')
+  Future<Response> getEnsemble(@Bind.path('id') int id) async {
+    final ensemble = await db.ensembleById(id).getSingle();
+    if (ensemble != null) {
+      return Response.ok(ensemble);
+    } else {
+      return Response.notFound();
+    }
+  }
+
+  @Operation.put('id')
+  Future<Response> putEnsemble(
+      @Bind.path('id') int id, @Bind.body() Map<String, dynamic> json) async {
+    final ensemble = Ensemble.fromJson(json).copyWith(
+      id: id,
+    );
+
+    await db.updateEnsemble(ensemble);
+
+    return Response.ok(null);
+  }
+}