AppVeyor broken

[jmthomas]

AppVeyor is failing all the time

An error occurred while loading ./spec/core_ext/cosmos_io_spec.rb.
Failure/Error: require 'ruby-prof' if RUBY_ENGINE == 'ruby'
LoadError:
  cannot load such file -- ruby_prof.so
# ./spec/spec_helper.rb:52:in `require'
# ./spec/spec_helper.rb:52:in `<top (required)>'
# ./spec/core_ext/cosmos_io_spec.rb:11:in `require'
# ./spec/core_ext/cosmos_io_spec.rb:11:in `<top (required)>'
# ./spec/spec_helper.rb:19:in `load'
# ./spec/spec_helper.rb:19:in `load'
# ------------------
# --- Caused by: ---
# LoadError:
#   cannot load such file -- 2.4.6/ruby_prof.so
#   ./spec/spec_helper.rb:52:in `require'
An error occurred while loading ./spec/core_ext/exception_spec.rb.