No reason for region on the stack really

Since you can get the region with Ref("AWS::Region") this is pretty
silly.  Only the builder needs to know for AWS connections.

stacker/builder.py

@@ -213,7 +213,7 @@ def build_template(self, stack_config):
             raise AttributeError("Stack class %s does not have a "
                                  "'rendered' "
                                  "attribute." % (class_path))
-        template = cls(self.region, name=stack_name, mappings=self.mappings,
+        template = cls(name=stack_name, mappings=self.mappings,
                        config=stack_config)
         self.stacks[stack_name].template = template
         return template

stacker/stack.py

@@ -9,9 +9,6 @@
 class StackTemplateBase(object):
     """Base implementation for dealing with a troposphere template.
 
-    :type region: string, AWS region
-    :param region: The AWS region where this stack will be deployed.
-
     :type name: string
     :param name: A name for the stack template. If not provided, one
         will be created from the class name automatically.
@@ -23,8 +20,7 @@ class StackTemplateBase(object):
     :param config: A dictionary which is used to pass in configuration info
         to the stack.
     """
-    def __init__(self, region, name, config, mappings=None):
-        self.region = region
+    def __init__(self, name, config, mappings=None):
         self.name = name
         self.mappings = mappings
         self.config = config