cocoapods-downloader does not support http downloads where url contains get params

[sglist]

1. Create a podspec where s.source contains a url with get params. For example:s.source = { :http => 'http://example.com/1/2?x=1&artifact=file.zip' }
2. Run pod install

Result: source fails to download

Installing MyPod (1.0.0)
[!] Pod::Executable -L -o /Users/user/MyPod/file.zip http://example.com/1/2?x=1&artifact=file.zip --create-dirs

sh: --create-dirs: command not found

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current

                                 Dload  Upload   Total   Spent    Left  Speed

100   708    0   708    0     0   5149      0 --:--:-- --:--:-- --:--:--  5167

Note: This could be fixed by quoting the url passed to curl:
https://github.com/CocoaPods/cocoapods-downloader/blob/master/lib/cocoapods-downloader/http.rb#L87

  def download_file(full_filename)
    curl! %|-L -o #{full_filename.shellescape} "#{url}" --create-dirs|
  end

[fabiopelosin]

The fix would be similar to this: 7b0e373