added apt-utils to debian systems

debian-7/Dockerfile

@@ -1,7 +1,7 @@
 FROM debian:7
 
 RUN apt-get -q update \
-    && apt-get install -y python-pip python-dev git
+    && apt-get install -y python-pip python-dev git apt-utils
 
 RUN pip install --index-url=https://pypi.python.org/simple/ --upgrade pip
 

debian-8/Dockerfile

@@ -9,6 +9,7 @@ RUN apt-get -q update \
       python-dev \
       python-pip \
       git \
+      apt-utils \
     && apt-get clean \
     && pip install --upgrade pip
 

ubuntu-14.04/Dockerfile

@@ -3,6 +3,7 @@ FROM ubuntu:14.04
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
       software-properties-common \
+      apt-utils \
     && apt-add-repository ppa:ansible/ansible \
     && apt-get update \
     && apt-get install -y --no-install-recommends \

ubuntu-16.04/Dockerfile

@@ -3,6 +3,7 @@ FROM ubuntu:16.04
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
       software-properties-common \
+      apt-utils \
     && apt-add-repository ppa:ansible/ansible \
     && apt-get update \
     && apt-get install -y --no-install-recommends \