<InputGroup size="sm">
    <Input name="input1" type="number" onKeyPress={this.onKeyPress.bind(this)}  value={this.state.point1}
    onChange={(e) => this.setInputValue(e, 'point1')}
    onBlur={() => this.setSliderValueFromInput('point1')} />
</InputGroup>
<InputGroup size="sm" >
    <Input name="input2" type="number" onKeyPress={this.onKeyPress.bind(this)} value={this.state.point2}
    onChange={(e) => this.setInputValue(e, 'point2')}
    onBlur={() => this.setSliderValueFromInput('point2')} />
</InputGroup>

onKeyPress(event) {
    const keyCode = event.keyCode || event.which;
    const keyValue = String.fromCharCode(keyCode);
     if (/+|-/.test(keyValue))
       event.preventDefault();
   }