Configure Bundler with RSpec and Nokogiri

RSpec provides a DSL for Behaviour-Driven development
Nokogiri can parse XML using XPath or CSS selectors
Handle degenerate case (blank document)
Add Pry to Gemfile
Handle fragment with one speaker and one line
Extract analyser into let to remove duplication
Handle one speaker with multiple lines
Support for multiple lines and multiple speakers
Sort results by descending lines per speaker
Increment the count correctly when a speaker has
multiple lines.
Remove unnecessary line
Remove commented-out line
Use clearer variable names when sorting
Add Runner
Rename classes for clarity
Add README notes