Fix corejs3 failure on fresh checkout

[matthargett]

On a fresh checkout, I was getting an error with the build and test targets:

$ rollup --config

src/ReactShallowRenderer.js → build/cjs/react-shallow-renderer.js...
[!] (plugin babel) Error: Cannot find module '@babel/compat-data/corejs3-shipped-proposals'
Require stack:
- /Users/mhargett/src/react-shallow-renderer/node_modules/@babel/preset-env/lib/polyfills/corejs3/usage-plugin.js
- /Users/mhargett/src/react-shallow-renderer/node_modules/@babel/preset-env/lib/index.js
- /Users/mhargett/src/react-shallow-renderer/node_modules/@babel/core/lib/config/files/plugins.js
- /Users/mhargett/src/react-shallow-renderer/node_modules/@babel/core/lib/config/files/index.js
- /Users/mhargett/src/react-shallow-renderer/node_modules/@babel/core/lib/index.js
- /Users/mhargett/src/react-shallow-renderer/node_modules/rollup-plugin-babel/dist/rollup-plugin-babel.cjs.js
- /Users/mhargett/src/react-shallow-renderer/rollup.config.js
- /Users/mhargett/src/react-shallow-renderer/node_modules/rollup/dist/bin/rollup

this was with nodejs 12.18.3 on MacOS 10.15. The bare minimum to fix the error is in the first commit, but I figured I would bump the rest of the packages to the same version so long as the build and tests passed.

Note that I couldn't update @babel/plugin-transform-classes package : any later version causes an error.

[NMinhNguyen]

Thanks for raising this. I just did a fresh checkout of the repo via git clone https://github.com/NMinhNguyen/react-shallow-renderer, ran yarn and yarn build and the build succeeded. But that was using Node.js 10, when I switched to 12, I was able to observe the same failure.

However, given that the published version of react-shallow-renderer works as is, I'd like to be very careful to avoid any possible regressions (see this comment from the React team facebook/react#18144 (review)) and hold off on merging this. There are a bunch of Dependabot updates that do the same but it's not a big priority and would require manually inspecting the bundle diff to ensure there's no regressions.

[NMinhNguyen]

Superseded by #93.