Handle error when polling

[michaelsanford]

Handle error in package polling to account for connectivity issues

go func(items chan []PullRequest) {
	for ; true; <-ticker.C {
		resp, _ := client.Do(req)
		bodyText, _ := ioutil.ReadAll(resp.Body)
		s := extract(string(bodyText))
		items <- s
	}
}(items)

https://golang.org/pkg/net/http/#Client.Do

Change the system tray icon and probably don't panic()?