fix docker file
diff --git a/Dockerfile b/Dockerfile
index 0b4fa60..bc44048 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@
     apt-get install -y software-properties-common && \
     add-apt-repository ppa:jonathonf/python-3.6 && \
     apt-get update &&  \
-    apt-get install -y vim git build-essential python3.6 python3.6-dev python3-pip python3.6-venv curl wget
+    apt-get install -y vim git build-essential python3.6 python3.6-dev python3-pip python3.6-venv python3.6-tk curl wget
 
 COPY . /opt/disk_perf_tool