chore(deps): update dependency karma-mocha to v2 (#797)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [karma-mocha](https://togithub.com/karma-runner/karma-mocha) | devDependencies | major | [`^1.3.0` -> `^2.0.0`](https://renovatebot.com/diffs/npm/karma-mocha/1.3.0/2.0.0) |

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### Release Notes

<details>
<summary>karma-runner/karma-mocha</summary>

### [`v2.0.0`](https://togithub.com/karma-runner/karma-mocha/blob/master/CHANGELOG.md#&#8203;200-httpsgithubcomkarma-runnerkarma-mochacomparev130v200-2020-04-14)

[Compare Source](https://togithub.com/karma-runner/karma-mocha/compare/v1.3.0...v2.0.0)

##### Features

-   **ci:** enable semanitic-release ([5a5b6d5](https://togithub.com/karma-runner/karma-mocha/commit/5a5b6d52399eab9a20592e3536b3e2df1b3ce9ce))
-   Expose 'pending' status ([e847121](https://togithub.com/karma-runner/karma-mocha/commit/e847121e35f59a498c3b09f87f138621b550629b)), closes [#&#8203;109](https://togithub.com/karma-runner/karma-mocha/issues/109)

-   Update Node.js versions ([fd64f5b](https://togithub.com/karma-runner/karma-mocha/commit/fd64f5bcacf2e0de6eeb24772384442bd6a37bed))

##### BREAKING CHANGES

-   drop support for node 8

</details>

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package.json

@@ -61,7 +61,7 @@
     "karma-child-process": "^1.0.3",
     "karma-chrome-launcher": "^3.0.0",
     "karma-coverage": "^2.0.0",
-    "karma-mocha": "^1.3.0",
+    "karma-mocha": "^2.0.0",
     "karma-remap-coverage": "^0.1.5",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^4.0.2",