updated fetch.js to use luxon instead of moment

[majesticio]

moment -> luxon

[github-actions]

results:

⛔⛔⛔⛔⛔⛔
The following packages are missing:
- babel-register is needed by /home/runner/work/openaq-fetch/openaq-fetch/run-scripts.js
- iconv is needed by /home/runner/work/openaq-fetch/openaq-fetch/src/adapters/moscow.js

There are 13 unused packages:

⚠⚠⚠⚠⚠⚠⚠⚠⚠
Unused dependencies:
- @babel/node
- core-js
- depcheck
- knex-postgis
- querystring
- require-dir
- wellknown
- winston-papertrail

⚠⚠⚠⚠⚠⚠⚠⚠⚠
Unused devDependencies:
- @babel/register
- @babel/runtime
- eslint-plugin-standard
- pg
- shell-escape

[majesticio]

merged into update-libraries