Fix clicking multiple times in an integration test

So far we only had tests that called Click() only once. If you have a test that
calls Click twice (we'll add one in the next commit), you'll notice that the
second click is interpreted as a drag because the mouse button wasn't released
in between. Fix this by sending a "mouse-up" event after the click.

pkg/gui/gui_driver.go

@@ -57,6 +57,11 @@ func (self *GuiDriver) Click(x, y int) {
 		0,
 	)
 	self.waitTillIdle()
+	self.gui.g.ReplayedEvents.MouseEvents <- gocui.NewTcellMouseEventWrapper(
+		tcell.NewEventMouse(x, y, tcell.ButtonNone, 0),
+		0,
+	)
+	self.waitTillIdle()
 }
 
 // wait until lazygit is idle (i.e. all processing is done) before continuing