manually remove fallback imports

Author: Mic92

Diff for: html5lib/_trie/_base.py

@@ -1,8 +1,5 @@
 
-try:
-    from collections.abc import Mapping
-except ImportError:  # Python 2.7
-    from collections.abc import Mapping
+from collections.abc import Mapping
 
 
 class Trie(Mapping):

Diff for: html5lib/_utils.py

@@ -1,10 +1,7 @@
 
 from types import ModuleType
 
-try:
-    from collections.abc import Mapping
-except ImportError:
-    from collections.abc import Mapping
+from collections.abc import Mapping
 
 from six import text_type, PY3
 

Diff for: html5lib/treebuilders/dom.py

@@ -1,9 +1,6 @@
 
 
-try:
-    from collections.abc import MutableMapping
-except ImportError:  # Python 2.7
-    from collections.abc import MutableMapping
+from collections.abc import MutableMapping
 from xml.dom import minidom, Node
 import weakref
 

Diff for: html5lib/treebuilders/etree_lxml.py

@@ -15,10 +15,7 @@
 import re
 import sys
 
-try:
-    from collections.abc import MutableMapping
-except ImportError:
-    from collections.abc import MutableMapping
+from collections.abc import MutableMapping
 
 from . import base
 from ..constants import DataLossWarning