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.

Conflicts:
	package.json