VOL-2131: Use base docker image

Also remove unused ponsim dockerfiles as
they are in their own repo now.

Change-Id: Ic9c1723ffd01afaefc9783374d467df061bbe737
diff --git a/python/docker/Dockerfile.ofagent b/python/docker/Dockerfile.ofagent
index 52ebaaa..73e8789 100644
--- a/python/docker/Dockerfile.ofagent
+++ b/python/docker/Dockerfile.ofagent
@@ -11,28 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-FROM ubuntu:16.04
-
-# Update to have latest images
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends \
-        ca-certificates=20170717~16.04.2 \
-	python=2.7.12-1~16.04 \
-	openssl=1.0.2g-1ubuntu4.15 \
-	iproute2=4.3.0-1ubuntu3.16.04.5 \
-	libpcap-dev=1.7.4-2 \
-	wget=1.17.1-1ubuntu1.5 \
-	build-essential=12.1ubuntu2 \
-	git=1:2.7.4-0ubuntu1.6 \
-	binutils=2.26.1-1ubuntu1~16.04.8 \
-	python-dev=2.7.12-1~16.04 \
-	libffi-dev=3.2.1-4 \
-	libssl-dev=1.0.2g-1ubuntu4.15 \
-	&& apt-get clean && rm -rf /var/lib/apt/lists/*
-
-# Install current version of pip rather than outdated pip from apt
-RUN wget -O /tmp/get-pip.py https://bootstrap.pypa.io/get-pip.py
-RUN python /tmp/get-pip.py
+FROM voltha/voltha-python-base:1.0.0
 
 # Install adapter requirements.
 COPY requirements.txt /tmp/requirements.txt