Update dependency gatsby to v2.18.2

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
gatsby	dependencies	patch	2.18.1 -> 2.18.2

---

Release Notes

gatsbyjs/gatsby

### [`v2.18.2`](https://togithub.com/gatsbyjs/gatsby/compare/gatsby@2.18.1...gatsby@2.18.2) [Compare Source](https://togithub.com/gatsbyjs/gatsby/compare/gatsby@2.18.1...gatsby@2.18.2)

---

Renovate configuration

:date: Schedule: At any time (no schedule defined).

:vertical_traffic_light: Automerge: Enabled.

:recycle: Rebasing: Whenever PR becomes conflicted, or if you modify the PR title to begin with "rebase!".

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

---

• [ ] If you want to rebase/retry this PR, check this box

---

Newsflash: Renovate has joined WhiteSource, and is now free for all use. Learn more or view updated terms and privacy policies.

[codecov[bot]]

Codecov Report

Merging #360 into master will not change coverage. The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #360   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           5      5           
  Lines          60     60           
  Branches       10     10           
=====================================
  Hits           60     60

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 2e92752...7f6ffd1. Read the comment docs.