Adds Windows compatibility. Open3 requires fork, so we need win32-open3.

lib/github/command.rb

@@ -1,4 +1,10 @@
-require 'open3'
+if Gem.win_platform?
+  require 'win32/open3'
+  warn "You must 'gem install win32-open3' to use the github command on Windows"
+  exit 1
+else
+  require 'open3'
+end
 
 module GitHub
   class Command