Revert "Update Docker Image (#308)" (#311)

This reverts commit 8822f2a1
diff --git a/Dockerfile b/Dockerfile
index 4815f81..afdda12 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,13 @@
-FROM python:3.6-alpine
+FROM buildpack-deps:xenial
 
 # install system deps
 RUN apt-get update
 RUN apt-get install -y \
+    python-pip \
+    python-dev \
     git \
+    gcc \
+    make \
     zlib1g-dev \
     libsasl2-dev \
     libsasl2-modules \