(deps): upgrade several deps' majors; require Node 10+

[agilgur5]

• officially drop support for Node <10 since many deps don't support it anymore

  • it has been EoL since Dec 31, 2019 and many deps are using newer, ES2017 language features now too
  • previously we deprecated it and semi-officially dropped, this time is fully official with engines requirement
  • and will be released as a breaking change

• camelcase, chalk, execa, and fs-extra all dropped Node <10

  • so did prettier v2 and rollup v2 which we will update to in the near future

• ora and rollup-plugin-sourcemaps dropped Node <8 in breaking bumps

  • so could've upgraded before, but for some reason some past Greenkeeper PRs were closed
  • and pascal-case upgrade didn't change any Node version support
  • Jest 25, which we will update to in the same breaking release, also dropped support for Node <8

• rollup-plugin-sourcemaps v0.5 is now written in TS and ships its own types, so no need for its @types/ counterpart anymore

• pascal-case changed to use named export instead of a default export

---

Node 10 bump

Officially drop Node 10 after deprecation in #426 and semi-official drop in #433 .

Also merges together a handful of Greenkeeper PRs that required Node 10+:

• Closes #665
• Closes #660
• Closes #629

And now Prettier v2 (#632) and Rollup v2 (#545) upgrades at least won't have to worry about this breakage (those do still have worry about other breakage still though 😅 )

Other dep upgrades

And some Greenkeeper PRs that were previously closed for unknown reasons but don't require Node 10+ ended up getting wrapped in here too (not intentionally, was just upgrading deps in general and looking for Node 10 requirements):

• Closes #313
• Closes #380
• Closes #326
• Closes #357

Based on https://github.com/jaredpalmer/tsdx/pull/323#issuecomment-561552649, it seems like at the time Greenkeeper made an automated PR for a minor version for some reason and maybe these were mistaken for the same thing. The CI failures fixed by #504 that made Greenkeeper open lots of issues around failing in-range updates may have also caused some other errors with Greenkeeper or confusion around it in general. Should be good now, though not totally sure why rollup-plugin-sourcemaps doesn't seem to have a Greenkeeper PR for it.

[vercel[bot]]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/formium/tsdx/ezzfl0hcs
✅ Preview: https://tsdx-git-fork-agilgur5-upgrade-node-10.formium.vercel.app

[agilgur5]

Rebased and tests still all pass, merging as getting ready to release v0.14.0 now that v0.13.3 has been released

[agilgur5]

Checked what all the deprecation warnings on a fresh install of v0.13.3 are per https://github.com/formium/tsdx/pull/789#issuecomment-695854530, and saw that this should fix two of them since they're transitive dependencies of rollup-plugin-sourcemaps v0.4.2, which was upgraded here to v0.5:

npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated // rollup-plugin-sourcemaps@0.4.2
npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated // rollup-plugin-sourcemaps@0.4.2