Add ability to turn off policy preload

You can now set environment variable to override whether or not the
policies are pre-loaded by the engines during docker image startup.

The README.md is updated with instructions. Each docker-compose has
a different default set.

The .env file is set to load policies by default to true. You can override
by either changing this file or setting the environment:

export PRELOAD_POLICIES=false

Issue-ID: POLICY-304
Change-Id: Ia96788ac3b8d47814eea1046d96c4e3e4a0b9664
Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/.env b/.env
new file mode 100644
index 00000000..0916ff2e
--- /dev/null
+++ b/.env
@@ -0,0 +1,2 @@
+PRELOAD_POLICIES=true
+