Fixing StringIO bug in 1.9.2

[arsduo]

Hey Nick,

Here's a fix for the StringIO bug I reported.

Without the fix, rake test produces:

(in /Users/ahkoppel2/Desktop/multipart-post)
............EF
Finished in 0.005231 seconds.

  1) Error:
test_form_multipart_body_with_stringio(Net::HTTP::Post::MultiPartTest):
NoMethodError: undefined method `path' for #<StringIO:0x000001011470b0>
    /Users/ahkoppel2/Desktop/multipart-post/lib/composite_io.rb:71:in `initialize'
    /Users/ahkoppel2/Desktop/multipart-post/test/net/http/post/test_multipart.rb:38:in `new'
    /Users/ahkoppel2/Desktop/multipart-post/test/net/http/post/test_multipart.rb:38:in `test_form_multipart_body_with_stringio'

  2) Failure:
test_works_with_ruby_192_string_ios(UploadIOTest) [/Users/ahkoppel2/Desktop/multipart-post/test/test_upload_io.rb:8]:
Exception raised:
<#<ArgumentError: wrong number of arguments (1 for 2)>>.

14 tests, 29 assertions, 1 failures, 1 errors, 0 skips

With the fix, we get

..............
Finished in 0.004948 seconds.

I originally wrote a StringIO-specific test (as you see in the results), but I removed it since one of the existing tests uses StringIOs and was failing without the fix.

Thanks again! The gem is very useful, and we're happy to help.

Best,

Alex

[nicksieger]

Thanks!