Fix bug with otp codes starting with zero being stripped

Author: Kieran Osgood

src/lib/index.jsx

@@ -139,7 +139,7 @@ class OtpInput extends Component<Props, State> {
   handleOtpChange = (otp: string[]) => {
     const { onChange, isInputNum } = this.props;
     const otpValue = otp.join('');
-    onChange(isInputNum ? Number(otpValue) : otpValue);
+    onChange(otpValue);
   };
 
   // Focus on input by index