Plugin Marketplace: Check engine field and avoid downloading incompatible updates

Summary: Only download plugins with "engine" version less or equal to the current Flipper version

Reviewed By: mweststrate

Differential Revision: D22211546

fbshipit-source-id: 52cf51badcd1e7041214d2a09ba6b6fc9c331b8f

desktop/app/src/__mocks__/electron.tsx

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+module.exports = {
+  remote: {
+    process: {
+      env: {},
+    },
+    app: {
+      getPath: (path: string) => `/${path}`,
+      getAppPath: process.cwd,
+      getVersion: () => '0.9.99',
+      relaunch: () => {},
+      exit: () => {},
+    },
+    getCurrentWindow: () => ({isFocused: () => true}),
+  },
+  ipcRenderer: {},
+};