Lots of TypeScript compilation errors when running webpack server

Checking this repo out, but I am having some issues with it. Any ideas? (I just cloned the repo and did a `yarn install`.) _Could_ be #12 but I'm unsure...

```
$ npm run-script start

> react-hot-ts@0.1.0 start /Volumes/extra/git/3rd-party/react-hot-ts
> webpack-dev-server

Project is running at http://localhost:8080/
webpack output is served from /

[at-loader] Using typescript@2.6.2 from typescript and "tsconfig.json" from /Volumes/extra/git/3rd-party/react-hot-ts/tsconfig.json.

[at-loader] Checking started in a separate process...

[at-loader] Checking finished with 174 errors
Hash: e68bb4bcf4aada26f5a8
Version: webpack 2.7.0
Time: 3813ms
Asset Size Chunks Chunk Names
bundle.js 1.3 MB 0 [emitted] [big] main
bundle.js.map 1.51 MB 0 [emitted] main
index.html 341 bytes [emitted]
chunk {0} bundle.js, bundle.js.map (main) 1.18 MB [entry] [rendered]
[./node_modules/react-hot-loader/lib/patch.js] ./~/react-hot-loader/lib/patch.js 209 bytes {0} [built]
[./node_modules/react-hot-loader/patch.js] ./~/react-hot-loader/patch.js 40 bytes {0} [built]
[./node_modules/react/react.js] ./~/react/react.js 56 bytes {0} [built]
[./node_modules/strip-ansi/index.js] ./~/strip-ansi/index.js 161 bytes {0} [built]
[./node_modules/url/url.js] ./~/url/url.js 23.3 kB {0} [built]
[./node_modules/webpack-dev-server/client/index.js?http:/localhost:8080] (webpack)-dev-server/client?http://localhost:8080 7.95 kB {0} [built]
[./node_modules/webpack-dev-server/client/overlay.js] (webpack)-dev-server/client/overlay.js 3.73 kB {0} [built]
[./node_modules/webpack-dev-server/client/socket.js] (webpack)-dev-server/client/socket.js 1.05 kB {0} [built]
[0] multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server react-hot-loader/patch ./src/index.tsx 64 bytes {0} [built]
[./node_modules/webpack/hot ^\.\/log$] (webpack)/hot nonrecursive ^\.\/log$ 160 bytes {0} [built]
[./node_modules/webpack/hot/dev-server.js] (webpack)/hot/dev-server.js 1.57 kB {0} [built]
[./node_modules/webpack/hot/emitter.js] (webpack)/hot/emitter.js 77 bytes {0} [built]
[./node_modules/webpack/hot/log-apply-result.js] (webpack)/hot/log-apply-result.js 1.02 kB {0} [built]
[./src/App.tsx] ./src/App.tsx 2.56 kB {0} [built]
[./src/index.tsx] ./src/index.tsx 1.65 kB {0} [built]
+ 362 hidden modules

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3542:13
TS2403: Subsequent variable declarations must have the same type. Variable 'a' must be of type 'DetailedHTMLProps, HTMLAnchorElement>', but here has type 'DetailedHTMLProps, HTMLAnchorElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3543:13
TS2403: Subsequent variable declarations must have the same type. Variable 'abbr' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3544:13
TS2403: Subsequent variable declarations must have the same type. Variable 'address' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3545:13
TS2403: Subsequent variable declarations must have the same type. Variable 'area' must be of type 'DetailedHTMLProps, HTMLAreaElement>', but here has type 'DetailedHTMLProps, HTMLAreaElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3546:13
TS2403: Subsequent variable declarations must have the same type. Variable 'article' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3547:13
TS2403: Subsequent variable declarations must have the same type. Variable 'aside' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3548:13
TS2403: Subsequent variable declarations must have the same type. Variable 'audio' must be of type 'DetailedHTMLProps, HTMLAudioElement>', but here has type 'DetailedHTMLProps, HTMLAudioElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3549:13
TS2403: Subsequent variable declarations must have the same type. Variable 'b' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3550:13
TS2403: Subsequent variable declarations must have the same type. Variable 'base' must be of type 'DetailedHTMLProps, HTMLBaseElement>', but here has type 'DetailedHTMLProps, HTMLBaseElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3551:13
TS2403: Subsequent variable declarations must have the same type. Variable 'bdi' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3552:13
TS2403: Subsequent variable declarations must have the same type. Variable 'bdo' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3553:13
TS2403: Subsequent variable declarations must have the same type. Variable 'big' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3554:13
TS2403: Subsequent variable declarations must have the same type. Variable 'blockquote' must be of type 'DetailedHTMLProps, HTMLElement>', but here has type 'DetailedHTMLProps, HTMLElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3555:13
TS2403: Subsequent variable declarations must have the same type. Variable 'body' must be of type 'DetailedHTMLProps, HTMLBodyElement>', but here has type 'DetailedHTMLProps, HTMLBodyElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3556:13
TS2403: Subsequent variable declarations must have the same type. Variable 'br' must be of type 'DetailedHTMLProps, HTMLBRElement>', but here has type 'DetailedHTMLProps, HTMLBRElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3557:13
TS2403: Subsequent variable declarations must have the same type. Variable 'button' must be of type 'DetailedHTMLProps, HTMLButtonElement>', but here has type 'DetailedHTMLProps, HTMLButtonElement>'.

ERROR in [at-loader] ./node_modules/@types/react-hot-loader/node_modules/@types/react/index.d.ts:3558:13
TS2403: Subsequent variable declarations must have the same type. Variable 'canvas' must be of type 'DetailedHTMLProps, HTMLCanvasElement>', but here has type 'DetailedHTMLProps, HTMLCanvasElement>'.

[...more similar errors]
```

Start by running yarn install and npm run-script start, then inspect tsconfig.json and the duplicate @types/react declarations reported under node_modules. Compare the TypeScript and React type-package setup involved in the errors; done means the webpack development server starts without the reported compilation errors.

Written by the indexing model from the issue text.