Add uae download in rt dockerfile (#534)

diff --git a/docker/teaclave-rt.ubuntu-1804.Dockerfile b/docker/teaclave-rt.ubuntu-1804.Dockerfile
index a7189f0..1d07d62 100644
--- a/docker/teaclave-rt.ubuntu-1804.Dockerfile
+++ b/docker/teaclave-rt.ubuntu-1804.Dockerfile
@@ -19,7 +19,8 @@
 RUN apt-get update && apt-get install -q -y \
     libsgx-launch=$VERSION \
     libsgx-urts=$VERSION \
-    libsgx-quote-ex=$VERSION
+    libsgx-quote-ex=$VERSION \
+    libsgx-uae-service=$VERSION
 RUN mkdir /etc/init
 
 # Install Intel SGX SDK for libsgx_urts_sim.so