Update github-pages plugin from version 193 to 197.

Fix #457
Fix #385

* update github-pages to v193

* rebuild gemfile.lock with ruby 2.5.3p105 [x64-mingw32]

* update to gh-pages 163

* removed "'" in tzinfo-data gem for local build

* quickfix to run blog on localhost without changing _config.yml

* windows fix for Gemfile, removes execjs and therubyracer from dependencies

Add vagrant support for easy local development