fix(store): deprecating registry.yarnpkg.com

[splincode]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ngxs/store/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[x] Build related changes
[x] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

yarnpkg/yarn#5891

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

unused package was removed ("rxjs-compat": "^6.0.0")

https://update.angular.io/
Remove deprecated RxJS 6 features using rxjs-tslint auto update rules
For most applications this will mean running the following two commands:

yarn global add rxjs-tslint
rxjs-5-to-6-migrate -p src/tsconfig.app.json

[markwhitfeld]

LGTM

[markwhitfeld]

From your instructions in the other Information section are there any breaking changes for our users? Or is it just for people building the lib?

[splincode]

@markwhitfeld no breaking changes because this library was a bridge to the outdated RxJS 5