Test failure TypeError on fresh create-probot-app from template checks-js with probot >8.0.0

Bug Report

Current Behavior Upgrading probot to 8.0.2 or 9.0.0 on a fresh create-probot-app (started with probot 7.5.1 set as "^7.2.0"), based on the checks-js template results in a test failure.

- code/probot-bug » npx create-probot-app my-first-app
npx: installed 215 in 5.068s

Let's create a Probot app!
Hit enter to accept the suggestion.

? App name: my-first-app
? Description of app: A Probot app
? Author's full name: Greg Burek
? Author's email address: [e-mail]
? Homepage:
? GitHub user or org name: gregburek
? Repository name: my-first-app
? Which template would you like to use? checks-js
[snip]
Finished scaffolding files!

Installing Node dependencies!
[snip]
- code/probot-bug » cd my-first-app
- probot-bug/my-first-app » npm run test

> my-first-app@1.0.0 test /Users/gburek/code/probot-bug/my-first-app
> jest && standard

  console.warn node_modules/before-after-hook/index.js:45
    [before-after-hook]: "Hook()" repurposing warning, use "Hook.Collection()". Read more: https://git.io/upgrade-before-after-hook-to-1.4

 PASS  test/index.test.js
  My Probot app
    ✓ creates a passing check (1061ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        3.545s
Ran all test suites.
- probot-bug/my-first-app » npm install probot@8
npm WARN deprecated probot@8.0.2: Update to Probot 9, both versios have been released at the same time by accedent. Sorry :(
npm WARN acorn-jsx@5.0.1 requires a peer of acorn@^6.0.0 but none is installed. You must install peer dependencies yourself.

+ probot@8.0.2
added 32 packages from 17 contributors, removed 7 packages, updated 3 packages and audited 479748 packages in 7.927s
found 0 vulnerabilities

- probot-bug/my-first-app » npm run test
 FAIL  test/index.test.js
  My Probot app
    ✕ creates a passing check (115ms)

  ● My Probot app › creates a passing check

    TypeError: this.app.getInstallationAccessToken is not a function

      at Application.<anonymous> (node_modules/probot/src/application.ts:496:46)
      at step (node_modules/probot/lib/application.js:40:23)
      at Object.next (node_modules/probot/lib/application.js:21:53)
      at node_modules/probot/lib/application.js:15:71
      at Object.<anonymous>.__awaiter (node_modules/probot/lib/application.js:11:12)
      at Object.auth (node_modules/probot/src/application.ts:495:15)
      at Promise.resolve.then (node_modules/@octokit/rest/plugins/authentication/before-request.js:50:20)

Expected behavior/code A passing test with latest probot lib

Environment

• Probot version(s): v8.0.2 and v9.0.0
• Node/npm version: v11.9.0/6.5.0
• OS: OSX 10.13.6

[kompiro]

I mock getInstallationAccessToken like below.

probot = new Probot({})
// Load our app into probot
const app = probot.load(myProbotApp)
 
// just return a test token
app.app = {
  getInstallationAccessToken: (option) => Promise.resolve('test')
}

[gr2m]

We have to update the tests for the new Probot. We have to pass in a valid app id and private key. This is just for reference, I’ll see how to make this easier

- probot = new Probot({})
- // Load our app into probot
- const app = probot.load(myProbotApp)
- 
- // just return a test token
- app.app = () => 'test'
+ probot = new Probot({
+   id: 123,
+   cert: `-----BEGIN RSA PRIVATE KEY-----
+ MIICXQIBAAKBgQC2RTg7dNjQMwPzFwF0gXFRCcRHha4H24PeK7ey6Ij39ay1hy2o
+ H9NEZOxrmAb0bEBDuECImTsJdpgI6F3OwkJGsOkIH09xTk5tC4fkfY8N7LklK+uM
+ ndN4+VUXTPSj/U8lQtCd9JnnUL/wXDc46wRJ0AAKsQtUw5n4e44f+aYggwIDAQAB
+ AoGAW2/cJs+WWNPO3msjGrw5CYtZwPuJ830m6RSLYiAPXj0LuEEpIVdd18i9Zbht
+ fL61eoN7NEuSd0vcN1PCg4+mSRAb/LoauSO3HXote+6Lhg+y5mVYTNkE0ZAW1zUb
+ HOelQp9M6Ia/iQFIMykhrNLqMG9xQIdLH8BDGuqTE+Eh8jkCQQDyR6qfowD64H09
+ oYJI+QbsE7yDOnG68tG7g9h68Mp089YuQ43lktz0q3fhC7BhBuSnfkBHwMztABuA
+ Ow1+dP9FAkEAwJeYJYxJN9ron24IePDoZkL0T0faIWIX2htZH7kJODs14OP+YMVO
+ 1CPShdTIgFeVp/HlAY2Qqk/do2fzyueZJwJBAN5GvdUjmRyRpJVMfdkxDxa7rLHA
+ huL7L0wX1B5Gl5fgtVlQhPhgWvLl9V+0d6csyc6Y16R80AWHmbN1ehXQhPkCQGfF
+ RsV0gT8HRLAiqY4AwDfZe6n8HRw/rnpmoe7l1IHn5W/3aOjbZ04Gvzg9HouIpaqI
+ O8xKathZkCKrsEBz6aECQQCLgqOCJz4MGIVHP4vQHgYp8YNZ+RMSfJfZA9AyAsgP
+ Pc6zWtW2XuNIGHw9pDj7v1yDolm7feBXLg8/u9APwHDy
+ -----END RSA PRIVATE KEY-----`
+ })
+ 
+ // Load our app into probot
+ probot.load(myProbotApp)