Zero downtime redeploys

When deploying check if there is already a container with the existing
name. If there is rename it to "<version>_<random_hex_string>" to remove
the name clash with the new container we want to boot.

We can then do the normal zero downtime run/wait/stop.

While implementing this I discovered the --filter name=foo does a
substring match for foo, so I've updated those filters to do an exact
match instead.

lib/mrsk/commands/healthcheck.rb

@@ -43,7 +43,7 @@ class Mrsk::Commands::Healthcheck < Mrsk::Commands::Base
     end
 
     def container_id
-      container_id_for(container_name: container_name)
+      container_id_for(container_name: container_name_with_version)
     end
 
     def health_url