Update dependency gatsby-transformer-sharp to v2.3.0

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
gatsby-transformer-sharp	dependencies	minor	2.2.23 -> 2.3.0

---

Release Notes

gatsbyjs/gatsby

### [`v2.3.0`](https://togithub.com/gatsbyjs/gatsby/compare/868b44f5522edd3fd09fbe68aaa6e995e3cdfe03...2f4c4608df62e867f646881a00a5141860b7f5e0) [Compare Source](https://togithub.com/gatsbyjs/gatsby/compare/868b44f5522edd3fd09fbe68aaa6e995e3cdfe03...2f4c4608df62e867f646881a00a5141860b7f5e0)

---

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

---

This PR has been generated by Renovate Bot. View repository job log here.

[codecov[bot]]

Codecov Report

Merging #322 into master will not change coverage. The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #322   +/-   ##
=====================================
  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 15b0748...58a0af6. Read the comment docs.