Upgrade Jekyll to 4.1.0

[chadokruse]

Jekyll 4.0 causes Codeship build to hit memory cap due to cacheing Jekyll 4.1.0 adds --disable-disk-cache flag

Interim fix: Keeping Jekyll at 3.8.6 allows builds to complete

• [x] DEPENDENCY: Wait for 4.1.0 release: https://github.com/jekyll/jekyll/releases
• [x] Update Codeship staging deploy script (see below)
• [x] Update Codeship source deploy script (see below)
• [x] Update Gemfile (remove jekyll version params)
• [x] Ensure Gemfile.lock is updated and committed to source
• [x] gitignore / Jekyll exclude / or rm -rf .bundle config directory created in Codeship (and committed to gh-pages)
• [ ] Test on staging branch

---

Codeship deploy script updates On both staging and source

# Prep Webpack
npm install
# Ensure Codeship uses proper version of Ruby
rvm use $(cat .ruby-version) --install
# Ensure using upgraded bundle version
# Pre-installed ruby packages on Codeship may have Bundle 1.0
gem install bundler
bundle install
# Run Webpack
npm run webpack

On source only

JEKYLL_ENV=production bundle exec jekyll build --disable-disk-cache