changed timepicker button keys to AM/PM

Author: camfletch

src/time-picker/clock.jsx

@@ -80,8 +80,8 @@ const Clock = React.createClass({
 
     if (this.props.format === 'ampm'){
       buttons = [
-        <ClockButton key="1" position="left" onTouchTap={this._setAffix.bind(this, "am")} selected={isAM} >{"AM"}</ClockButton>,
-        <ClockButton key="2" position="right" onTouchTap={this._setAffix.bind(this, "pm")} selected={!isAM} >{"PM"}</ClockButton>,
+        <ClockButton key="AM" position="left" onTouchTap={this._setAffix.bind(this, "am")} selected={isAM} >{"AM"}</ClockButton>,
+        <ClockButton key="PM" position="right" onTouchTap={this._setAffix.bind(this, "pm")} selected={!isAM} >{"PM"}</ClockButton>,
       ];
     }
     return buttons;