Bump the version of Rake
Robustify server startup
Bump the versions of pry and rspec
source :rubygems is deprecated
Kill the max-retries stuff
Pry::Method#source can raise on Rubinius
Pry::Method#source raises on Rubinius

https://github.com/pry/pry/issues/955
(setq robe-running nil) on failed request
Fix some tests on Rubinius
Get rid of should_receive
Don't test for IO::readable and IO::writable anywhere but MRI

They have different names and no owned methods on Rbx, and don't exist
on JRuby.