use env var for db path

main.go

@@ -8,6 +8,7 @@ import (
 	_ "github.com/mattn/go-sqlite3"
 	"log"
 	"math"
+	"os"
 	"strconv"
 	"time"
 )
@@ -110,9 +111,10 @@ func main() {
 		ulimit = t
 	}
 
+	dbpath := os.Getenv("XBIT_DB")
 	var db TimelineDB
 	var err error
-	db.DB, err = sql.Open("sqlite3", "./timeline.db")
+	db.DB, err = sql.Open("sqlite3", dbpath)
 	if err != nil {
 		log.Fatal(err)
 	}