chore(deps): update dependency ts-loader to v7 (#965)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [ts-loader](https://github.com/TypeStrong/ts-loader) | devDependencies | major | [`^6.2.1` -> `^7.0.0`](https://renovatebot.com/diffs/npm/ts-loader/6.2.2/7.0.0) |

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### Release Notes

<details>
<summary>TypeStrong/ts-loader</summary>

### [`v7.0.0`](https://github.com/TypeStrong/ts-loader/blob/master/CHANGELOG.md#v700)

[Compare Source](https://github.com/TypeStrong/ts-loader/compare/v6.2.2...v7.0.0)

-   [Project reference support enhancements](https://github.com/TypeStrong/ts-loader/pull/1076) - thanks [@&#8203;sheetalkamat](https://github.com/sheetalkamat)!
-   Following the end of life of Node 8, `ts-loader` no longer supports Node 8 **BREAKING CHANGE**

</details>

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package.json

@@ -92,7 +92,7 @@
     "proxyquire": "^2.0.0",
     "sinon": "^9.0.0",
     "tmp": "^0.1.0",
-    "ts-loader": "^6.2.1",
+    "ts-loader": "^7.0.0",
     "typescript": "3.6.4",
     "uuid": "^7.0.0",
     "webpack": "^4.42.0",