apply best practice of emptying /var/lib/apt/lists/* after apt-get run
diff --git a/containers/xos/Dockerfile.base b/containers/xos/Dockerfile.base
index d89e6e8..319e5f4 100644
--- a/containers/xos/Dockerfile.base
+++ b/containers/xos/Dockerfile.base
@@ -43,7 +43,8 @@
     rsync \
     supervisor \
     tar \
-    wget
+    wget \
+ && rm -rf /var/lib/apt/lists/*
 
 # Install python pacakges with pip
 RUN pip install \
@@ -106,9 +107,8 @@
     # git clone uses cached copy, doesn't pick up latest
     git -C /opt/ansible pull && \
     git -C /opt/ansible/lib/ansible/modules/core pull && \
-    git -C /opt/ansible/v2/ansible/modules/core pull
-
-RUN mkdir -p /usr/local/share /bin /etc/ansible
+    git -C /opt/ansible/v2/ansible/modules/core pull && \
+    mkdir -p /usr/local/share /bin /etc/ansible
 
 COPY ansible-hosts /etc/ansible/hosts