Lock down to GitHub API v3 for future compatibility

Every API request will now declare that it wants v3 by setting
"Accept: application/vnd.github.v3+json".

http://developer.github.com/v3/media/

features/checkout.feature

@@ -11,6 +11,7 @@ Feature: hub checkout <PULLREQ-URL>
     Given the GitHub API server:
       """
       get('/repos/mojombo/jekyll/pulls/77') {
+        halt 406 unless request.env['HTTP_ACCEPT'] == 'application/vnd.github.v3+json'
         json :head => {
           :label => 'mislav:fixes',
           :repo => { :private => false }

features/fork.feature

@@ -42,6 +42,7 @@ Feature: hub fork
     Given the GitHub API server:
       """
       get('/repos/mislav/dotfiles') {
+        halt 406 unless request.env['HTTP_ACCEPT'] == 'application/vnd.github.v3+json'
         json :parent => { :html_url => 'https://github.com/unrelated/dotfiles' }
       }
       """

lib/hub/github_api.rb

@@ -123,7 +123,7 @@ module Hub
       res.error! unless res.success?
       raw_url = res.data['files'].values.first['raw_url']
       res = get(raw_url) do |req|
-        req['Accept'] = '*/*'
+        req['Accept'] = 'text/plain'
       end
       res.error! unless res.success?
       res.body
@@ -228,6 +228,7 @@ module Hub
         req['User-Agent'] = "Hub #{Hub::VERSION}"
         apply_authentication(req, url)
         yield req if block_given?
+        finalize_request(req, url)
 
         begin
           res = http.start { http.request(req) }
@@ -261,6 +262,12 @@ module Hub
         req.basic_auth user, pass
       end
 
+      def finalize_request(req, url)
+        if !req['Accept'] || req['Accept'] == '*/*'
+          req['Accept'] = 'application/vnd.github.v3+json'
+        end
+      end
+
       def create_connection url
         use_ssl = 'https' == url.scheme
 

test/hub_test.rb

@@ -190,7 +190,7 @@ class HubTest < Minitest::Test
       }))
 
     stub_request(:get, "https://gist.github.com/raw/8da7fb575debd88c54cf/SHA/file.diff").
-      with(:headers => {'Accept'=>'*/*'}).
+      with(:headers => {'Accept'=>'text/plain'}).
       to_return(:status => 200)
 
     with_tmpdir('/tmp/') do