Routes: Fixed vpc_peering_connection_id in describe route tables.
Deleted Stack Fix and ValidationError for DescribeStacks.

  * stop backed from trying to iterate over empty list of deleted stacks.
  * Update DescribeStacks to throw ValidationError if stack name or id doesn't exist.
Add test for bad describe stack request
Routes: Fixed vpc_peering_connection_id in describe route tables. (Upgrade: Boto 2.32.1 ~> 2.34.0)
create_stack returns stack_id
test delete stack
Routes: Fixed vpc_peering_connection_id in describe route tables. (Travis: Revert Python 3 tests to use Boto 2.32.1)
python 2.6 assert_raises
use the current ec2 backend, not necessarily us-east-1, for vpc operations
remove some test details for 2.6
use the current ec2 backend, not the default, for subnets
Pass ec2_backend to Instance constructor

This value is used to look up things like nics and subnets in that
backend.
Merge pull request #242 from djmitche/regionalize_vpcs

use the current ec2 backend, not necessarily us-east-1, for some operations
Merge pull request #243 from djmitche/regionalize_instances

Pass ec2_backend to Instance constructor
Merge pull request #240 from joekiller/fix/describe_stacks_add_validation_error

Fix/describe stacks add validation error
EC2: Add support for the IncludeAllInstances option in DescribeInstanceStatus
Add describe instance status test for new option
Merge pull request #241 from DreadPirateShawn/RouteVPCPeeringConnection

Route vpc peering connection
Some fixes for dynamodb and python 3.
Fix boto version.