Fixes not enough time for docker restart before continuing on to next

provisioning step

plugins/provisioners/docker/cap/debian/docker_configure_auto_start.rb

@@ -9,6 +9,10 @@ module VagrantPlugins
                 comm.sudo("echo 'DOCKER_OPTS=\"-r=true ${DOCKER_OPTS}\"' >> /etc/default/docker")
                 comm.sudo("stop docker")
                 comm.sudo("start docker")
+                [0, 1, 2, 4].each do |delay|
+                  sleep delay
+                  break if comm.test('test -f /var/run/docker.pid')
+                end
               end
             end
           end