Make container dind unpin old docker relase

- remove pinning to old docker version in ubuntu
- move docker ubuntu repository to base image

Change-Id: If05ccc0c5b3e89725acea3b603b5ef7acbbee649
Partially-implements: blueprint build-debian

docker/base/Dockerfile.j2

@@ -212,6 +212,7 @@ COPY apt_preferences.{{ base_distro }} /etc/apt/preferences
       '430BDF5C56E7C94E848EE60C1C4CBDCDCD2EFD2A',
       '08B73419AC32B4E966C1A330E84AC2C0460F3994',
       '46095ACC8548582C1A2699A9D27D666CD88E42B4',
+      '58118E89F3A912897C070ADBF76221572C52609D',
     ] %}
 {% elif base_distro == 'debian' %}
     {% set keys = [

docker/base/sources.list.ubuntu

@@ -24,3 +24,6 @@ deb http://packages.elastic.co/elasticsearch/2.x/debian stable main
 
 # Kibana repo
 deb http://packages.elastic.co/kibana/4.4/debian stable main
+
+# Docker repo
+deb http://apt.dockerproject.org/repo ubuntu-trusty main

docker/dind/Dockerfile.j2

@@ -10,12 +10,10 @@ RUN /bin/true
 
 {% elif base_distro in ['ubuntu', 'debian'] %}
 
-RUN echo 'deb http://apt.dockerproject.org/repo ubuntu-trusty main' > /etc/apt/sources.list.d/docker.list \
+RUN apt-get update \
-    && apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D \
-    && apt-get update \
     && apt-get -y install --no-install-recommends \
         btrfs-tools \
-        docker-engine=1.8.2-0~trusty \
+        docker-engine \
         openssh-server \
     && apt-get clean \
     && pip --no-cache-dir install --upgrade docker-py