Update dependency eslint-config-prettier to v6.15.0

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
eslint-config-prettier	dependencies	minor	6.14.0 -> 6.15.0

---

Release Notes

prettier/eslint-config-prettier

v6.15.0

Compare Source

• Added: [@​typescript-eslint/space-infix-ops]. Thanks to Masafumi Koba (@​ybiquitous)!!

---

Renovate configuration

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

🚦 Automerge: Disabled due to failing status checks.

♻️ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 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 WhiteSource Renovate. View repository job log here.

[renovate]

⚠️ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻️ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you check the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: package-lock.json

npm WARN old lockfile 
npm WARN old lockfile The package-lock.json file was created with an old version of npm,
npm WARN old lockfile so supplemental metadata must be fetched from the registry.
npm WARN old lockfile 
npm WARN old lockfile This is a one-time fix-up, please be patient...
npm WARN old lockfile 
npm ERR! code EBADENGINE
npm ERR! engine Unsupported engine
npm ERR! engine Not compatible with your version of node/npm: cson-parser@4.0.5
npm ERR! notsup Not compatible with your version of node/npm: cson-parser@4.0.5
npm ERR! notsup Required: {"node":">=8","npm":"^6.0.0"}
npm ERR! notsup Actual:   {"npm":"7.0.3","node":"v15.0.1"}

npm ERR! A complete log of this run can be found in:
npm ERR!     /tmp/renovate-cache/others/npm/_logs/2020-10-27T19_14_43_338Z-debug.log

[KingDarBoja]

Fixed by #791