Changes to docker image

- Remove .git and utils folders from container.
- Set memory limit to 128M and make sure sessions last 1 week.

Change-Id: I3ab9e12a1948270045ec68bf0727bdc5862385ff
diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..5feee53
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,2 @@
+.git
+utils