fix(deps): update dependency mocha to v8 (#3228)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [mocha](https://mochajs.org/) ([source](https://github.com/mochajs/mocha)) | dependencies | major | [`^7.0.0` -> `^8.0.0`](https://renovatebot.com/diffs/npm/mocha/7.2.0/8.0.1) |

---

### Release Notes

<details>
<summary>mochajs/mocha</summary>

### [`v8.0.1`](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md#&#8203;801--2020-06-10)

[Compare Source](https://github.com/mochajs/mocha/compare/v8.0.0...v8.0.1)

The obligatory patch after a major.

#### 🐛 Fixes

-   [#&#8203;4328](https://github.com/mochajs/mocha/issues/4328): Fix `--parallel` when combined with `--watch` ([**@&#8203;boneskull**](https://github.com/boneskull))

### [`v8.0.0`](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md#&#8203;800--2020-06-10)

[Compare Source](https://github.com/mochajs/mocha/compare/v7.2.0...v8.0.0)

In this major release, Mocha adds the ability to _run tests in parallel_. Better late than never! Please note the **breaking changes** detailed below.

Let's welcome [**@&#8203;giltayar**](https://github.com/giltayar) and [**@&#8203;nicojs**](https://github.com/nicojs) to the maintenance team!

#### 💥 Breaking Changes

-   [#&#8203;4164](https://github.com/mochajs/mocha/issues/4164): **Mocha v8.0.0 now requires Node.js v10.12.0 or newer.** Mocha no longer supports the Node.js v8.x line ("Carbon"), which entered End-of-Life at the end of 2019 ([**@&#8203;UlisesGascon**](https://github.com/UlisesGascon))

-   [#&#8203;4175](https://github.com/mochajs/mocha/issues/4175): Having been deprecated with a warning since v7.0.0, **`mocha.opts` is no longer supported** ([**@&#8203;juergba**](https://github.com/juergba))

    ✨ **WORKAROUND:** Replace `mocha.opts` with a [configuration file](https://mochajs.org/#configuring-mocha-nodejs).

-   [#&#8203;4260](https://github.com/mochajs/mocha/issues/4260): Remove `enableTimeout()` (`this.enableTimeout()`) from the context object ([**@&#8203;craigtaub**](https://github.com/craigtaub))

    ✨ **WORKAROUND:** Replace usage of `this.enableTimeout(false)` in your tests with `this.timeout(0)`.

-   [#&#8203;4315](https://github.com/mochajs/mocha/issues/4315): The `spec` option no longer supports a comma-delimited list of files ([**@&#8203;juergba**](https://github.com/juergba))

    ✨ **WORKAROUND**: Use an array instead (e.g., `"spec": "foo.js,bar.js"` becomes `"spec": ["foo.js", "bar.js"]`).

-   [#&#8203;4309](https://github.com/mochajs/mocha/issues/4309): Drop support for Node.js v13.x line, which is now End-of-Life ([**@&#8203;juergba**](https://github.com/juergba))

-   [#&#8203;4282](https://github.com/mochajs/mocha/issues/4282): `--forbid-only` will throw an error even if exclusive tests are avoided via `--grep` or other means ([**@&#8203;arvidOtt**](https://github.com/arvidOtt))

-   [#&#8203;4223](https://github.com/mochajs/mocha/issues/4223): The context object's `skip()` (`this.skip()`) in a "before all" (`before()`) hook will no longer execute subsequent sibling hooks, in addition to hooks in child suites ([**@&#8203;juergba**](https://github.com/juergba))

-   [#&#8203;4178](https://github.com/mochajs/mocha/issues/4178): Remove previously soft-deprecated APIs ([**@&#8203;wnghdcjfe**](https://github.com/wnghdcjfe)):

    -   `Mocha.prototype.ignoreLeaks()`
    -   `Mocha.prototype.useColors()`
    -   `Mocha.prototype.useInlineDiffs()`
    -   `Mocha.prototype.hideDiff()`

#### 🎉 Enhancements

-   [#&#8203;4245](https://github.com/mochajs/mocha/issues/4245): Add ability to run tests in parallel for Node.js (see [docs](https://mochajs.org/#parallel-tests)) ([**@&#8203;boneskull**](https://github.com/boneskull))

    ❗ See also [#&#8203;4244](https://github.com/mochajs/mocha/issues/4244); [Root Hook Plugins (docs)](https://mochajs.org/#root-hook-plugins) -- _root hooks must be defined via Root Hook Plugins to work in parallel mode_

-   [#&#8203;4304](https://github.com/mochajs/mocha/issues/4304): `--require` now works with ES modules ([**@&#8203;JacobLey**](https://github.com/JacobLey))

-   [#&#8203;4299](https://github.com/mochajs/mocha/issues/4299): In some circumstances, Mocha can run ES modules under Node.js v10 -- _use at your own risk!_ ([**@&#8203;giltayar**](https://github.com/giltayar))

#### 📖 Documentation

-   [#&#8203;4246](https://github.com/mochajs/mocha/issues/4246): Add documentation for parallel mode and Root Hook plugins ([**@&#8203;boneskull**](https://github.com/boneskull))

#### 🔩 Other

-   [#&#8203;4200](https://github.com/mochajs/mocha/issues/4200): Drop mkdirp and replace it with fs.mkdirSync ([**@&#8203;HyunSangHan**](https://github.com/HyunSangHan))

#### 🐛 Fixes

(All bug fixes in Mocha v8.0.0 are also breaking changes, and are listed above)

</details>

---

### Renovate configuration

📅 **Schedule**: "after 9am and before 3pm" (UTC).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻️ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#googleapis/gapic-generator).

showcase/nodejs/package.json

@@ -14,7 +14,7 @@
     "karma-chrome-launcher": "^3.1.0",
     "karma-mocha": "^2.0.0",
     "karma-webpack": "^4.0.2",
-    "mocha": "^7.0.0",
+    "mocha": "^8.0.0",
     "null-loader": "^4.0.0",
     "puppeteer": "^4.0.0",
     "webpack": "^4.39.3",