Work on #12: Move each providers in their own packages

alerting/provider/pagerduty/pagerduty_test.go

@@ -0,0 +1,14 @@
+package pagerduty
+
+import "testing"
+
+func TestAlertProvider_IsValid(t *testing.T) {
+	invalidProvider := AlertProvider{IntegrationKey: ""}
+	if invalidProvider.IsValid() {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{IntegrationKey: "00000000000000000000000000000000"}
+	if !validProvider.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}