Add check if job is already done

src/lib.rs

@@ -258,6 +258,11 @@ impl BenchmarkRepository
 		Some(content.to_owned())
 	}
 
+	pub fn is_job_done(&self, key: &str) -> bool
+	{
+		self.file_exists(Path::new(key), "results")
+	}
+
 	pub fn create_job(&mut self, key: String) -> &Job
 	{
 		let id = self.jobs.len() as u32;