Attempt publish with updated Gemfile/bundler version

Also adds slicer-up.sh experimental script for getting
the blog running natively without Docker.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Author: alexellis

.dockerignore

@@ -0,0 +1,4 @@
+/.bundle/**
+/_site/**
+/tmp/**
+/slicer/**

.gitignore

@@ -6,3 +6,6 @@ _site
 vendor
 /tmp
 /files.txt
+/slicer/**
+/*.img
+/vm_agent_secret