Panic when the consul-alerts/reminders/ is empty

[moadqassem]

Go version: go.11.1
OS: MacOS Mojave
Consul Version: 1.4.2
Consul-Alerts Version: 0.5.0

Description:

When a user creates manually an empty reminder folder (e.g: consul-alerts/reminders/ ), the consul-alerts binary simply panics and that panic doesn't recover which would kill the watching process.

The reason for the panic is, there is no check to see if the reminders folder has some subfolders or not.

panic: runtime error: index out of range

goroutine 1 [running]:
github.com/AcalephStorage/consul-alerts/consul.(*ConsulAlertClient).UpdateCheckData(0xc420290000)
	/go/src/github.com/AcalephStorage/consul-alerts/consul/client.go:306 +0xe98
github.com/AcalephStorage/consul-alerts/consul.NewClient(0xc4200cc30e, 0xe, 0xc4200cc3fd, 0x3, 0xc42002653c, 0x2, 0x1b, 0xc420143c88, 0x40d0e5)
	/go/src/github.com/AcalephStorage/consul-alerts/consul/client.go:63 +0x28f
main.daemonMode(0xc4201c0e10)
	/go/src/github.com/AcalephStorage/consul-alerts/consul-alerts.go:144 +0x66e
main.main()
	/go/src/github.com/AcalephStorage/consul-alerts/consul-alerts.go:58 +0xf4

[moadqassem]

Here is the PR which solves the issue: #250