Add .dockerignore file

Change-Id: I8d4b527a2e5c7b69e5c7338cafba3fbdac381ae1
diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..1b2211d
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1 @@
+build*