make checkbox values ellipsis (#277)

* make checkbox values ellipsis

* remoce unused classname

src/MultiValueControl.tsx

@@ -86,7 +86,7 @@ export class MultiValueControl extends React.Component<IMultiValueControlProps,
             />
             <FocusZone
                 direction={FocusZoneDirection.vertical}
-                className="checkboxes"
+              
             >
                 {this.state.filter ? null :
                 <Checkbox
@@ -106,7 +106,7 @@ export class MultiValueControl extends React.Component<IMultiValueControlProps,
                         onFocus: this._onFocus,
                     }}
                     onChange={() => this._toggleOption(o)}
-                    label={this._wrapText(o)}
+                    label={this._wrapText(o.length > 30 ? `${o.slice(0, 30)}...` : o)}
                     title={o}
                 />)}
             </FocusZone>