Log Message:
Update ruby-jekyll-archives to 2.1.1.

### Minor Enhancements

 * Make Archive subclass of Page (#67)
 * Don't limit slugs/title to strings (#41)

### Development Fixes

 * Update Travis config and Gemfile for Ruby < 2.2.2 support (#68)
 * Consolidate History file to work with jekyllbot (#80)