Make API match the README, remove StringResponse.

For YajlResponse the JSON body was being returned directly instead of
the response object, which conflicted with the README. I also removed
the StringResponse class since it wasn't really being used.

README.rdoc

@@ -1,6 +1,6 @@
 = faraday
 
-experiments in a rest api lib
+Experiments in a REST API lib
 
 Super alpha!  Don't use it if you mind throwing away all the code when I change
 the API on a whim.

lib/faraday/response/string_response.rb

@@ -1,9 +0,0 @@
-module Faraday
-  class Response
-    class StringResponse < Response
-      def content
-        body
-      end
-    end
-  end
-end

lib/faraday/response/yajl_response.rb

@@ -3,7 +3,6 @@ module Faraday
   class Response
     class YajlResponse < Response
       attr_reader :body
-      alias content body
 
       def initialize(headers = nil, body = nil)
         super

test/adapter_test.rb

@@ -15,14 +15,9 @@ class AdapterTest < Faraday::TestCase
         assert_equal 'hello world', @connection.get('hello_world').body
       end
 
-      it "retrieves the response JSON with StringResponse" do
-        @connection.response_class = Faraday::Response::StringResponse
-        assert_equal 'hello world', @connection.get('hello_world')
-      end
-
-      it "retrieves the response JSON with YajlResponse" do
+      it "retrieves the response body with YajlResponse" do
         @connection.response_class = Faraday::Response::YajlResponse
-        assert_equal [1,2,3], @connection.get('json')
+        assert_equal [1,2,3], @connection.get('json').body
       end
 
       it "retrieves the response headers" do

test/response_test.rb

@@ -11,23 +11,13 @@ class ResponseTest < Faraday::TestCase
     end
   end
 
-  describe "TestConnection#get with Faraday::StringResponse class" do
-    it "returns string body" do
-      conn = TestConnection.new do |stub|
-        stub.get('/hello') { [200, {}, 'hello world']}
-      end
-      conn.response_class = Faraday::Response::StringResponse
-      assert_equal 'hello world', conn.get('/hello')
-    end
-  end
-
   describe "TestConnection#get with Faraday::YajlResponse class" do
     it "returns string body" do
       conn = TestConnection.new do |stub|
         stub.get('/hello') { [200, {}, '[1,2,3]']}
       end
       conn.response_class = Faraday::Response::YajlResponse
-      assert_equal [1,2,3], conn.get('/hello')
+      assert_equal [1,2,3], conn.get('/hello').body
     end
   end
 end