Fix <Icon>'s not using tooltip and fix toolbar not being boolean (#3038)

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/renderer/components/dock/dock-tab.tsx

@@ -94,7 +94,7 @@ export class DockTab extends React.Component<DockTabProps> {
         {!pinned && (
           <Icon
             small material="close"
-            title="Close (Ctrl+Shift+W)"
+            tooltip="Close (Ctrl+Shift+W)"
             onClick={prevDefault(this.close)}
           />
         )}