Use `npm ci` to install fresh node_modules and cache the npm cache

See merge request !82

Problem: halley!12 (comment 550980140)

Where we also fixed this in `halley`, halley!12 (comment 550996537)

From

 - https://docs.gitlab.com/ee/ci/caching/#cache-nodejs-dependencies
 - gitlab-org/gitlab!25758

We are now installing dependencies from the [`npm ci`](https://docs.npmjs.com/cli/v7/commands/npm-ci) call.

> If a node_modules is already present, it will be automatically removed before npm ci begins its install.

This ensures, we have a clean `./node_modules` to install from every time which works well for our `graceful-fs` trick. And we just cache the npm cache so the clean install is fast.

`node_modules/` is in the cache so they are available for the next `test` job

Use Node.js v14 in CI

See merge request !81

Use script from webapp!2157 (comment 542684404)
to update graceful-fs (gulp dependency).

Part of https://gitlab.com/gitterHQ/webapp/-/issues/2735

Update the release process after the last release

See merge request gitlab-org/gitter/sidecar!80

1.5.0

Resolve "Reduce sidecar.v1.js size"

Closes #75

See merge request gitlab-org/gitter/sidecar!78

Ivan Malov authored Nov 15, 2019 and Tomas Vik committed Nov 15, 2019

- Remove postcss plugin stack
- Return webpack as builder
- Remove bower_components and react preset from rollup bundle, minor reformat code
- Add support spread operator instead for in
- Update PostCSS version for gulp
- Update README with contributing information
- Replaced the webpack with rollup for sidecar chat
- Remove es6-promise dependency
- Add size-limit
- Remove Array.from polyfill
- Remove object-assign polyfill
- Update node version and add .idea folder to .gitignore

Fix repository url

See merge request gitlab-org/gitter/sidecar!76

Release/1.4.2

See merge request gitlab-org/gitter/sidecar!75

Update example links from GitHub to GitLab

See merge request gitlab-org/gitter/sidecar!74

Identified typo implementing this issue
https://github.com/prest/prest.github.io/pull/27

Migrate to GitLab CI

See merge request gitlab-org/gitter/sidecar!73

Use local Selenium server for testing (instead of relying on BrowserStack)

use rel="noopener" on external links

Do not override "Array.from" with shim version if it is available.

See https://github.com/gitterHQ/sidecar/pull/68

Revert "Do not override "Array.from" with shim version if it is available."

Do not override "Array.from" with shim version if it is available.