changed http based tests, added #scheme, using it to correctly set no proxy domain

test/http_test.rb

@@ -100,7 +100,7 @@ class HTTPTest < Minitest::Test
 
   private
 
-  def origin(orig = httpbin)
-    "http://#{orig}"
+  def scheme
+    "http://"
   end
 end

test/https_test.rb

@@ -180,7 +180,7 @@ class HTTPSTest < Minitest::Test
 
   private
 
-  def origin(orig = httpbin)
-    "https://#{orig}"
+  def scheme
+    "https://"
   end
 end

test/support/http_helpers.rb

@@ -23,6 +23,10 @@ module HTTPHelpers
   end
 
   def httpbin_no_proxy
-    URI(ENV.fetch("HTTPBIN_NO_PROXY_HOST", "httpbin.org"))
+    URI(ENV.fetch("HTTPBIN_NO_PROXY_HOST", "#{scheme}httpbin.org"))
+  end
+
+  def origin(orig = httpbin)
+    "#{scheme}#{orig}"
   end
 end