Add current timestamp to filename

src/target.ts

@@ -16,6 +16,7 @@ export class Target {
   private day: number;
   private csvStream: any;
   private metric: Metric;
+  private createdTimestamp: number; 
 
   constructor(
     private panelUrl: string,
@@ -81,7 +82,7 @@ export class Target {
     }
     this.csvStream.end();
   }
-
+  // TODO: move csv-related stuff to service
   private initCsvStream() {
     this.csvStream = csv.createWriteStream({ headers: true });
     let writableStream = fs.createWriteStream(this.getFilePath('csv'));
@@ -107,7 +108,10 @@ export class Target {
   }
 
   private getFilename(extension) {
-    return `${this.datasourceName}.${this.from}-${this.to}.${extension}`;
+    if(this.createdTimestamp === undefined) {
+      this.createdTimestamp = moment().valueOf();
+    }
+    return `${this.createdTimestamp}.${this.datasourceName}.${extension}`;
   }
 
   private getFilePath(extension) {