Hover rating step configuration

[gilson-lopes-git]

I'm submitting a...

[ ] Bug report  
[x] Feature request

Current behavior

On hover the rating jumps one by one(1 star, 2 stars...)

Expected behavior

i'd like to have them jump half by half(0.5 star, 1 star, 1.5 stars...)

<star-rating [starType]="'svg'" [hoverEnabled]="true" [hoverStep]="'half'">

Environment

Library version: ^4.0.0-beta.3
Angular version: ^6.0.6

[ZoSo1974]

This would be very useful!