Remove ngrx-unique-reducers-action rule

[timdeschryver]

With ngrx/platform#2103 merged in NgRx, we don't need the rule ngrx-unique-reducers-action anymore.
So we can remove the rule, the spec for this rule, and the documentation.

• https://github.com/timdeschryver/ngrx-tslint-rules/blob/master/src/rules/ngrxUniqueReducerActionsRule.ts
• https://github.com/timdeschryver/ngrx-tslint-rules/tree/master/test/rules/unique-reducer-actions
• https://github.com/timdeschryver/ngrx-tslint-rules/blob/master/src/recommended.ts#L8
• https://github.com/timdeschryver/ngrx-tslint-rules/blob/master/README.md

[danny95djb]

I'm up for giving this a go.

[timdeschryver]

Awesome! 🎉

[timdeschryver]

🎉 This issue has been resolved in version 1.8.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀