Upgrade FFI to Ruby 2.3 issues on windows

[ksubrama]

No description provided.

[ksubrama]

@chris-rock
/cc @jkeiser : If you run into other weird loading errors on Windows when bumping to ruby 2.3, it's because of FFI incompatibility:

C:/Ruby23/lib/ruby/gems/2.3.0/gems/ffi-1.9.10-x86-mingw32/lib/ffi.rb:6:in `require': cannot load such file -- ffi_c (Loa
dError)
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/ffi-1.9.10-x86-mingw32/lib/ffi.rb:6:in `rescue in <top (required)>'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/ffi-1.9.10-x86-mingw32/lib/ffi.rb:3:in `<top (required)>'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/win32-process-0.8.3/lib/win32/process/functions.rb:6:in `require'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/win32-process-0.8.3/lib/win32/process/functions.rb:6:in `<top (required)
>'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/win32-process-0.8.3/lib/win32/process.rb:1:in `require_relative'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/win32-process-0.8.3/lib/win32/process.rb:1:in `<top (required)>'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/mixlib-shellout-2.2.7-universal-mingw32/lib/mixlib/shellout/windows.rb:2
1:in `require'
        from C:/Ruby23/lib/ruby/gems/2.3.0/gems/mixlib-shellout-2.2.7-universal-mingw32/lib/mixlib/shellout/windows.rb:2
1:in `<top (required)>'```