Add MongoDB 3.6 with some predefined policies

@tziai @valerii.kalashnikov

env/policy.env

+LOG_LEVEL="debug"
 HTTP_HOST=""
 HTTP_PORT="8080"
 HTTP_IDLE_TIMEOUT="120s"
@@ -7,4 +8,9 @@ REDIS_ADDR="redis:6379"
 REDIS_USER=""
 REDIS_PASS=""
 REDIS_DB=1
-REDIS_EXPIRATION="1h"
\ No newline at end of file
+REDIS_EXPIRATION="1h"
+MONGO_ADDR="mongodb://mongo:27017/policy?authSource=admin"
+MONGO_USER="root"
+MONGO_PASS="root"
+MONGO_DBNAME="policy"
+MONGO_COLLECTION="policies"
\ No newline at end of file