Pass the encoding parameter to the parse method in all cases

Pass the encoding parameter to the parse method even when using Python 3,
since there are some cases when you need to specify it. Use None as the
default encoding value, respecting html5lib's encoding detection logic.

microdata.py

@@ -11,19 +11,14 @@
     import simplejson as json
 
 
-def get_items(location, encoding='UTF-8'):
+def get_items(location, encoding=None):
     """
     Pass in a string or file-like object and get a list of Items present in the
     HTML document.
     """
     dom_builder = html5lib.treebuilders.getTreeBuilder("dom")
     parser = html5lib.HTMLParser(tree=dom_builder)
-
-    if (sys.version_info.major == 3):
-        tree = parser.parse(location)
-    else:
-        tree = parser.parse(location, encoding=encoding)
-
+    tree = parser.parse(location, encoding=encoding)
     return _find_items(tree)