fix props type

Author: javadbat

lib/JBDateInput.tsx

@@ -35,8 +35,8 @@ export type JBDateInputProps = {
     label?: string,
     style?:string,
     name?:string,
-    min?: string,
-    max?: string,
+    min: string | null | undefined,
+    max: string | null | undefined,
     format?: string,
     className?:string,
     onKeyup?: (e:JBDateInputEventType<KeyboardEvent>)=>void,