TT#50954 Force docker image regeneration

This should pick up the updated perlcritic config.

Change-Id: I41d29943f64223ab0a4b10cdd23c52af8fddcdd7

t/tap-tests-docker/Dockerfile

@@ -5,7 +5,7 @@ FROM docker.mgm.sipwise.com/sipwise-jessie:latest
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT 2018-06-21
+ENV REFRESHED_AT 2019-02-27
 
 RUN echo "# generated by Dockerfile from jenkins-tap-test-jessie at $(date)\n\
 deb https://deb.sipwise.com/autobuild/ internal-jessie main\n" > /etc/apt/sources.list.d/sipwise-internal.list