TT#29456 Create prosody-stretch docker for luacheck

Change-Id: If222e847dee53c9911de4ff664187b76f513c0e6

t/Dockerfile

@@ -1,5 +1,5 @@
-# DOCKER_NAME=prosody-jessie
-FROM docker.mgm.sipwise.com/sipwise-jessie:latest
+# DOCKER_NAME=prosody-stretch
+FROM docker.mgm.sipwise.com/sipwise-stretch:latest
 
 # Important! Update this no-op ENV variable when this Dockerfile
 # is updated with the current date. It will force refresh of all
@@ -7,7 +7,6 @@ FROM docker.mgm.sipwise.com/sipwise-jessie:latest
 # old cached versions when the Dockerfile is built.
 ENV REFRESHED_AT 2018-01-18
 
-RUN echo "deb https://deb.sipwise.com/autobuild internal-jessie main" >>/etc/apt/sources.list
 RUN apt-get update && apt-get install --assume-yes lua-check
 
 RUN echo './t/testrunner' >>/root/.bash_history
@@ -20,17 +19,13 @@ WORKDIR /code/
 # When you want to build the base image from scratch
 # jump to the next section if you don't want to build yourself!:
 #
-# you need to put the proper NGCP sources at t/sources.list.d/builddeps.list
-# for instance, trunk:
-# echo "deb https://deb.sipwise.com/autobuild/ release-trunk-jessie main" > t/sources.list.d/builddeps.list
-#
-# % docker build --tag="prosody-jessie" -f t/Dockerfile .
-# % docker run --rm -i -t -v $(pwd):/code:rw prosody-jessie:latest bash
+# % docker build --tag="prosody-stretch" -f t/Dockerfile .
+# % docker run --rm -i -t -v $(pwd):/code:rw prosody-stretch:latest bash
 #
 # Use the existing docker image:
-# % docker pull docker.mgm.sipwise.com/prosody-jessie
+# % docker pull docker.mgm.sipwise.com/prosody-stretch
 # NOTE: run the following command from root folder of git repository:
-# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/prosody-jessie:latest bash
+# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/prosody-stretch:latest bash
 #
 # Inside docker (the command is in history, just press UP button):
 #   ./t/testrunner