Add option to specify config file

main.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"flag"
+
 	"github.com/librespeed/speedtest/config"
 	"github.com/librespeed/speedtest/database"
 	"github.com/librespeed/speedtest/results"
@@ -9,9 +11,21 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-func main() {
-	conf := config.Load()
+var (
+	optConfig = flag.String("c", "", "config file to be used, defaults to settings.toml in the same directory")
+)
 
+func main() {
+	flag.Parse()
+
+	var conf config.Config
+	if *optConfig != "" {
+		conf = config.LoadFile(*optConfig)
+	} else {
+		conf = config.Load()
+	}
+
+	web.SetServerLocation(&conf)
 	results.Initialize(&conf)
 	database.SetDBInfo(&conf)
 	log.Fatal(web.ListenAndServe(&conf))