Remove future usage

Fixes mozilla-releng#102

mozilla_version/gecko.py

@@ -49,8 +49,6 @@
 import attr
 import re
 
-from future.utils import raise_from
-
 from mozilla_version.errors import (
     PatternNotMatchedError, TooManyTypesError, NoVersionTypeError
 )
@@ -435,11 +433,10 @@ def bump_version_type(self):
         try:
             return self.__class__(**self._create_bump_version_type_kwargs())
         except (ValueError, PatternNotMatchedError) as e:
-            # TODO Use "raise from" statement once Python 2 support is dropped
-            raise_from(ValueError(
+            raise ValueError(
                 'Cannot bump version type for version "{}". New version number is not valid. '
                 'Cause: {}'.format(self, e)
-            ), e)
+            ) from e
 
     def _create_bump_version_type_kwargs(self):
         bump_version_type_kwargs = {

mozilla_version/version.py

@@ -4,7 +4,6 @@
 import re
 
 from enum import Enum
-from future.utils import raise_from
 
 from mozilla_version.errors import MissingFieldError, PatternNotMatchedError
 from mozilla_version.parser import (
@@ -140,10 +139,9 @@ def bump(self, field):
         try:
             return self.__class__(**self._create_bump_kwargs(field))
         except (ValueError, PatternNotMatchedError) as e:
-            # TODO Use "raise from" statement once Python 2 support is dropped
-            raise_from(ValueError(
+            raise ValueError(
                 'Cannot bump "{}". New version number is not valid. Cause: {}'.format(field, e)
-            ), e)
+            ) from e
 
     def _create_bump_kwargs(self, field):
         if field not in self._ALL_NUMBERS:

requirements/base.in

@@ -1,2 +1 @@
 attrs>=19.2
-future

requirements/base.txt

@@ -1,4 +1,4 @@
-# SHA1:0cbc8244f71df4bd36c582a4c80da9cee81903db
+# SHA1:a19b4a7f9ecfb318d714b82b4c4c501d9ea30586
 #
 # This file is autogenerated by pip-compile-multi
 # To update, run:
@@ -9,6 +9,3 @@ attrs==22.2.0 \
     --hash=sha256:29e95c7f6778868dbd49170f98f8818f78f3dc5e0e37c0b1f474e3561b240836 \
     --hash=sha256:c9227bfc2f01993c03f68db37d1d15c9690188323c067c641f1a35ca58185f99
     # via -r requirements/base.in
-future==0.18.3 \
-    --hash=sha256:34a17436ed1e96697a86f9de3d15a3b0be01d8bc8de9c1dffd59fb8234ed5307
-    # via -r requirements/base.in