fix(deps): update dependency @google-cloud/common to v3 (#367)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [@google-cloud/common](https://togithub.com/googleapis/nodejs-common) | dependencies | major | [`^2.0.0` -> `^3.0.0`](https://renovatebot.com/diffs/npm/@google-cloud%2fcommon/2.4.0/3.0.0) |

---

### Release Notes

<details>
<summary>googleapis/nodejs-common</summary>

### [`v3.0.0`](https://togithub.com/googleapis/nodejs-common/blob/master/CHANGELOG.md#&#8203;300-httpswwwgithubcomgoogleapisnodejs-commoncomparev240v300-2020-03-26)

[Compare Source](https://togithub.com/googleapis/nodejs-common/compare/v2.4.0...v3.0.0)

##### ⚠ BREAKING CHANGES

-   drop support for node.js 8 ([#&#8203;554](https://togithub.com/googleapis/nodejs-common/issues/554))
-   remove support for custom promises ([#&#8203;541](https://togithub.com/googleapis/nodejs-common/issues/541))

##### Features

-   add progress events ([#&#8203;540](https://www.github.com/googleapis/nodejs-common/issues/540)) ([1834059](https://www.github.com/googleapis/nodejs-common/commit/18340596ecb61018e5427371b9b5a120753ec003))

##### Bug Fixes

-   remove support for custom promises ([#&#8203;541](https://www.github.com/googleapis/nodejs-common/issues/541)) ([ecf1c16](https://www.github.com/googleapis/nodejs-common/commit/ecf1c167927b609f13dc4fbec1954ff3a2765344))
-   **deps:** update dependency [@&#8203;google-cloud/projectify](https://togithub.com/google-cloud/projectify) to v2 ([#&#8203;553](https://www.github.com/googleapis/nodejs-common/issues/553)) ([23030a2](https://www.github.com/googleapis/nodejs-common/commit/23030a25783cd091f4720c25a15416c91e7bd0a0))
-   **deps:** update dependency [@&#8203;google-cloud/promisify](https://togithub.com/google-cloud/promisify) to v2 ([#&#8203;552](https://www.github.com/googleapis/nodejs-common/issues/552)) ([63175e0](https://www.github.com/googleapis/nodejs-common/commit/63175e0c4504020466a95e92c2449bdb8ac47546))

##### Miscellaneous Chores

-   drop support for node.js 8 ([#&#8203;554](https://www.github.com/googleapis/nodejs-common/issues/554)) ([9f41047](https://www.github.com/googleapis/nodejs-common/commit/9f410477432893f68e57b5eeb31a068a3d8ef52f))

</details>

---

### Renovate configuration

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

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

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

:no_bell: **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/nodejs-dns).

packages/google-cloud-dns/package.json

@@ -43,7 +43,7 @@
     "prelint": "cd samples; npm link ../; npm i"
   },
   "dependencies": {
-    "@google-cloud/common": "^2.0.0",
+    "@google-cloud/common": "^3.0.0",
     "@google-cloud/paginator": "^3.0.0",
     "@google-cloud/promisify": "^1.0.0",
     "arrify": "^2.0.0",