In our app, we want to open a popup/modal on a user action and then close it either by clicking on the close button inside the modal or anywhere outside of it. 

Let's build a sample Modal app and see how it'll work in a step-by-step fashion. Later, we can implement it in the Kanban app. Open the terminal and create a modal app: meteor create modal. To save on typing and installing packages one by one, copy and replace this package.json file with the one that was generated by Meteor. Then, run  npm install:

{
 "name": "modal",
 "private": true,
 "scripts": {
 "start": "meteor run"
},
 "dependencies": {
 "babel-runtime": "6.18.0",
 "classnames": "^2.2.5",
 "meteor-node-stubs": "~0.2.0",
 "react": "^15.4.2"
},
 "babel": {
  "plugins": [
  "transform-class-properties"
  ]
},
 "devDependencies": {
 "babel-plugin-transform-class-properties": "^6.19.0"
 }
}

To keep it clear and descriptive, we will create the Modal app with just four files. Delete all the default files in the client...