Add support for Gatsby v4, change dependencies

[arturparkhisenko]

Hi, @alvinometric 👋 I've decided to update it a bit to remove the warning and update some dependencies for the year 2021. Full changelog:

• Added Gatsby v4 to the peer dependencies
• Changed Babel dependencies and configs to the latest versions
• Changed configs for Node v12
• Changed other dependencies without changes cross-env, eslint, eslint-config-prettier, husky, lint-staged, prettier

And please, as a part of the Hacktoberfest OSS initiative, I wanted to ask you to add the label hacktoberfest-accepted if that PR will be accepted and merged, thanks!

[arturparkhisenko]

I guess I need to tag the current maintainer @garetmckinley , if you can look at it :) thanks!

[ghost]

Hello, I wish I had write access to this repo. I would totally merge this! I wasn't even aware that Gatsby had a v4.

And I was out there trying to make my dependencies work with v3 😅

[ilyvion]

@alvinometric You seem to have write access now; any thoughts on moving this forward? I'm upgrading my site and I'm getting this, which is sad.

Plugin gatsby-remark-reading-time is not compatible with your gatsby version 4.10.3 - It requires gatsby@^2.0.0

[aitchkhan]

@alvinometric any updates here please? :)

[alvinometric]

Hey, I have access to the repo, but I can't publish the updated code to npm, unfortunately

[arturparkhisenko]

cc'ing @garetmckinley then?