Remove AbstractCheckboxChangeEvent, fix TS4029 error

See https://github.com/Microsoft/TypeScript/issues/9944

components/checkbox/Checkbox.tsx

@@ -27,18 +27,16 @@ export interface CheckboxProps extends AbstractCheckboxProps<CheckboxChangeEvent
   indeterminate?: boolean;
 }
 
-export interface AbstractCheckboxChangeEvent<T> {
-  target: T;
-  stopPropagation: () => void;
-  preventDefault: () => void;
-  nativeEvent: MouseEvent;
-}
-
 export interface CheckboxChangeEventTarget extends CheckboxProps {
   checked: boolean;
 }
 
-export type CheckboxChangeEvent = AbstractCheckboxChangeEvent<CheckboxChangeEventTarget>;
+export interface CheckboxChangeEvent {
+  target: CheckboxChangeEventTarget;
+  stopPropagation: () => void;
+  preventDefault: () => void;
+  nativeEvent: MouseEvent;
+}
 
 export default class Checkbox extends React.Component<CheckboxProps, {}> {
   static Group: typeof CheckboxGroup;

components/radio/interface.tsx

@@ -1,6 +1,6 @@
 import * as React from 'react';
 import { AbstractCheckboxGroupProps } from '../checkbox/Group';
-import { AbstractCheckboxProps, AbstractCheckboxChangeEvent } from '../checkbox/Checkbox';
+import { AbstractCheckboxProps } from '../checkbox/Checkbox';
 
 export interface RadioGroupProps extends AbstractCheckboxGroupProps {
   defaultValue?: any;
@@ -33,4 +33,9 @@ export interface RadioChangeEventTarget extends RadioProps {
   checked: boolean;
 }
 
-export type RadioChangeEvent = AbstractCheckboxChangeEvent<RadioChangeEventTarget>;
+export interface RadioChangeEvent {
+  target: RadioChangeEventTarget;
+  stopPropagation: () => void;
+  preventDefault: () => void;
+  nativeEvent: MouseEvent;
+}