fixing docker build to debian jessie

Change-Id: I7a0523692eeafd7b1dacca4c3abc96484ce4562c
diff --git a/tools/build/docker/Dockerfile b/tools/build/docker/Dockerfile
index 6b0421a..98561ca 100644
--- a/tools/build/docker/Dockerfile
+++ b/tools/build/docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian
+FROM debian:jessie
 MAINTAINER Ali Al-Shabibi <ali@onlab.us>
 
 # Add Java 8 repository