Handle error returns from lookup

- see spec/fixtures/lookup-404.json for format

lib/faraday/raise_http_4xx.rb

@@ -40,7 +40,12 @@ def self.error_body(body)
       elsif body['error']
         ": #{body['error']}"
       elsif body['errors']
-        ": #{body['errors'].to_a.first.chomp}"
+        first = body['errors'].to_a.first
+        if first.kind_of? Hash
+          ": #{first['message'].chomp}"
+        else
+          ": #{first.chomp}"
+        end
       end
     end
   end

spec/faraday/raise_http_4xx_spec.rb

@@ -69,6 +69,22 @@
 
   end
 
+  context "when response status is 404 from lookup" do
+
+    before do
+      stub_get("users/lookup.json").
+        with(:query => {:screen_name => "not_on_twitter"}).
+        to_return(:status => 404, :body => fixture('lookup-404.json'))
+    end
+
+    it "should raise Twitter::NotFound" do
+      lambda do
+        @client.users('not_on_twitter')
+      end.should raise_error(Twitter::NotFound)
+    end
+
+  end
+
   context "when response status is 406" do
 
     before do

spec/fixtures/lookup-404.json

@@ -0,0 +1 @@
+{ "errors": [ { "code": 17, "message": "No user matches for specified terms" } ] }