Add `@types/sinon`

package.json

@@ -91,6 +91,7 @@
     "@types/qs": "^6.5.1",
     "@types/react": "^16.3.1",
     "@types/react-dom": "^16.0.4",
+    "@types/sinon": "^4.3.1",
     "arraybuffer-loader": "^1.0.3",
     "asar": "^0.14.0",
     "bower": "^1.8.2",

yarn.lock

@@ -83,6 +83,10 @@
   version "16.3.1"
   resolved "https://registry.yarnpkg.com/@types/react/-/react-16.3.1.tgz#6f6aaffaf7dba502ff5ca15e4aa18caee9b04995"
 
+"@types/sinon@^4.3.1":
+  version "4.3.1"
+  resolved "https://registry.yarnpkg.com/@types/sinon/-/sinon-4.3.1.tgz#32458f9b166cd44c23844eee4937814276f35199"
+
 "@vxna/mini-html-webpack-template@^0.1.6":
   version "0.1.6"
   resolved "https://registry.yarnpkg.com/@vxna/mini-html-webpack-template/-/mini-html-webpack-template-0.1.6.tgz#64225d564da5fe610b6445523c245572923c00b8"