changes as per PR comments

Author: GokulSNath

src/bubble/types.d.ts

@@ -1,13 +1,13 @@
 import { ReactElement } from "react";
-import { IStep } from "../stepper-component/types";
+import { IStep, IStyleFunction } from "../stepper-component/types";
 
 export interface IBubbleProps {
     step: IStep,
     renderAdornment?(step: IStep, index: number): ReactElement,
     index: number,
     currentStepIndex?: number,
     handleStepClick(): void,
-    getBubbleStyles?(step: IStep, index: number): object,
-    getActiveBubbleStyles?(step: IStep, index: number): object,
-    getInActiveBubbleStyles?(step: IStep, index: number): object,
+    getBubbleStyles?: IStyleFunction,
+    getActiveBubbleStyles?: IStyleFunction,
+    getInActiveBubbleStyles?: IStyleFunction
 }