Merge pull request #5 from fleveque/master

Adding Kaminari and Chef
add Web Crawling section
add Foreman
Add posix-spawn
Merge pull request #6 from andycox/patch-2

Add posix-spawn
add GitHub Explore
add perftools.rb to Profilers section
add chruby and ruby-install

Once you go `chruby` you never go back. It doesn't rhyme, but it's true :laughing:
'bhf gem added to 'Admin Interface'
Merge pull request #7 from mrfoto/patch-1

add chruby and ruby-install
add vcr
Merge pull request #8 from antpaw/patch-1

'bhf' gem added to 'Admin Interface'
Merge pull request #9 from rmoriz/master

add vcr gem
Add Sucker Punch
Merge pull request #10 from brandonhilkert/patch-1

Add Sucker Punch