Move the "X-Phx" header addition to middleware

lib/faraday/request/phoenix.rb

@@ -0,0 +1,18 @@
+require 'faraday'
+
+module Faraday
+  class Request::Phoenix < Faraday::Middleware
+    def call(env)
+      # Not sure what what the X-Phx (Phoenix?) header is for but it's
+      # required to access certain undocumented resources
+      # e.g. GET urls/resolve
+      env[:request_headers]['X-Phx'] = 'true'
+
+      @app.call(env)
+    end
+
+    def initialize(app)
+      @app = app
+    end
+  end
+end

lib/twitter/connection.rb

@@ -1,4 +1,5 @@
 require 'faraday_middleware'
+require 'faraday/request/phoenix'
 require 'faraday/request/multipart_with_file'
 require 'faraday/request/gateway'
 require 'faraday/request/twitter_oauth'
@@ -14,11 +15,7 @@ def connection(format=format, temp_api_endpoint=nil)
       options = {
         :headers => {
           'Accept' => "application/#{format}",
-          'User-Agent' => user_agent,
-          # Not sure what what the X-Phx (Phoenix?) header is for but it's
-          # required to access certain undocumented resources
-          # e.g. GET urls/resolve
-          'X-Phx' => 'true',
+          'User-Agent' => user_agent
         },
         :proxy => proxy,
         :ssl => {:verify => false},
@@ -27,6 +24,7 @@ def connection(format=format, temp_api_endpoint=nil)
       options[:url] = temp_api_endpoint ? temp_api_endpoint : api_endpoint
 
       Faraday.new(options) do |builder|
+        builder.use Faraday::Request::Phoenix
         builder.use Faraday::Request::MultipartWithFile
         builder.use Faraday::Request::TwitterOAuth, authentication if authenticated?
         builder.use Faraday::Request::Multipart