misc: Added missing optional dependencies to 18.04 Docker

Change-Id: Ibc43664f99ce9fbd28d14352243fb17b7754289b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28892
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/util/dockerfiles/ubuntu-18.04_all-dependencies/Dockerfile b/util/dockerfiles/ubuntu-18.04_all-dependencies/Dockerfile
index a0064b6..95511a8 100644
--- a/util/dockerfiles/ubuntu-18.04_all-dependencies/Dockerfile
+++ b/util/dockerfiles/ubuntu-18.04_all-dependencies/Dockerfile
@@ -30,4 +30,5 @@
 RUN apt -y upgrade
 RUN apt -y install build-essential git m4 scons zlib1g zlib1g-dev \
     libprotobuf-dev protobuf-compiler libprotoc-dev libgoogle-perftools-dev \
-    python-dev python python-six doxygen
+    python-dev python python-six doxygen libboost-all-dev libhdf5-serial-dev \
+    python-pydot libpng-dev