News features and improvements (#8)

* added config file implementation, refactoring

* add gitignore

* improved test

* preperations for more metrics

* added resource metrics

* added first bgp metrics

* added asn as label for bgp metrics

* added prefix and message counts to bgp metrics

* simplified

* Update README.md

* added yaml dependency

* fixed go routine call

* added timeout

* clean up

* added TLS support

* set default api port for TLS

* added routes metric

* added missing log information

collector/metric_collector.go

@@ -0,0 +1,12 @@
+package collector
+
+import (
+	"github.com/nshttpd/mikrotik-exporter/config"
+	"github.com/prometheus/client_golang/prometheus"
+	routeros "gopkg.in/routeros.v2"
+)
+
+type metricCollector interface {
+	describe(ch chan<- *prometheus.Desc)
+	collect(ch chan<- prometheus.Metric, device *config.Device, client *routeros.Client) error
+}