Upgrade dependent packages to latest version

[yhatt]

This PR will upgrade dependent packages to latest version by using yarn upgrade(-interactive) --latest.

About security

Have you heard about a recent malicious dependency? The update of nodemon in this PR is beating a deep dependency completely.

npm has published a post about detail of the event-stream incident. Marpit and our packages managed by marp-team have already handled the incident in early (#96: last Sunday).

Next action

To manage packages securely, we're going to run yarn audit when running CI or publishing to npm.

[yhatt]

CI build was failed by updating deep dep by yarn upgrade --latest.

$ stylelint "./**/*.{css,scss}"
internal/modules/cjs/loader.js:582
    throw err;
    ^

Error: Cannot find module 'ajv/lib/compile/equal'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:580:15)
    at Function.Module._load (internal/modules/cjs/loader.js:506:25)
    at Module.require (internal/modules/cjs/loader.js:636:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (/home/circleci/marp-core/node_modules/table/dist/validateConfig.js:2:13)
    at Module._compile (internal/modules/cjs/loader.js:688:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:699:10)
    at Module.load (internal/modules/cjs/loader.js:598:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:537:12)
    at Function.Module._load (internal/modules/cjs/loader.js:529:3)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
Exited with code 1

I guess that is caused by minor update of ajv v6.6.0. Similar issues have reported in the other OSS. (e.g. next.js)

[yhatt]

It's a workaround for stylelint and ESLint to prevent error caused by the refactor in ajv.

@marp-team/[email protected]
├─┬ [email protected]
│ ├── [email protected]
│ └─┬ [email protected]
│   └── [email protected]  deduped
└─┬ [email protected]
  └── [email protected]  deduped