add rspec gem
add blogpost.rb with spec
add pry gem
add nokogiri gem
Blogpost#fetch atom feed
add vcr gem with webmock
use vcr for Blogpost#fetch
Blogpost#author initialized only with 2 words
add Blogpost#relative_url
custom Blogpost#to_yaml
keep empty _posts directory
ignore _posts directory contents
export blogpost to file
update Blogpost#fetch cassette
use vcr for Blogpost#fetch
lazy require jekyll
spec equality of blogposts
refactor Blogpost#export_to specs
fix type in comment
Blogpost.fetch not #fetch