Stacker

Bugfix release- primarily to deal with a bug that's been around since the
introduction of interactive mode/changesets. The bug primarily deals with the
fact that we weren't deleting Changesets that were not submitted. This didn't
affect anyone for the longest time, but recently people have started to hit
limits on the of changesets in an account. The current thinking is that the
limits weren't enforced before, and only recently has been enforced.

- Add S3 remote package sources [GH-487]
- Make blueprint dump always create intermediate directories [GH-499]
- Allow duplicate keys for most config mappings except `stacks` [GH-507]
- Remove un-submitted changesets [GH-513]

This is a minor update to help deal with some of the issues between `stacker`
and `stacker_blueprints` both having dependencies on `troposphere`. It loosens
the dependencies, allowing stacker to work with any reasonably new version
of troposphere (anything greater than `1.9.0`). `stacker_blueprints` will
likely require newer versions of troposphere, as new types are introduced to
the blueprints, but it's unlikely we'll change the `troposphere` version string
for stacker, since it relies on only the most basic parts of the `troposphere`
API.

This release is mostly about updating the dependencies for stacker to newer
versions, since that was missed in the last release.

- `--max-zones` removed from CLI [GH-427]
- Ami lookup: add region specification [GH-433]
- DynamoDB Lookup [GH-434]
- Environment file is optional now [GH-436]
- New functional test suite [GH-439]
- Structure config object using Schematics [GH-443]
- S3 endpoint fallback [GH-445]
- Stack specific tags [GH-450]
- Allow disabling of stacker bucket (direct CF updates) [GH-451]
- Uniform deprecation warnings [GH-452]
- Remote configuration support [GH-458]
- TroposphereType updates [GH-462]
- Fix replacements-only issue [GH-464]
- testutil enhancments to blueprint testing [GH-467]
- Removal of Interactive Provider (now combined w/ default provider) [GH-469]
- protected stacks [GH-472]
- MUCH Better handling of stack rollbacks & recreations [GH-473]
- follow\_symlinks argument for aws lambda hook [GH-474]
- Enable service\_role for cloudformation operations [GH-476]
- Allow setting stack description from config [GH-477]
- Move S3 templates into sub-directories [GH-478]

- Kinesis streams blueprint [GH-1]
- simple network blueprint [GH-2]
- YAML tests [GH-5]
- Support Route53 RecordSetGroups [GH-6]
- Add ECR Policies [GH-8]
- Generic EC2 Security Group Blueprint [GH-9]
- EC2 Role Blueprint [GH-22]
- ACM Certificates blueprint [GH-24]
- ECS blueprints [GH-30]
- Add EFS Blueprint [GH-129]
- simple ec2 instance blueprint [GH-164]
- replace get\_fqn instances with AWS::StackName [GH-165]
- DynamoDB Autoscaling blueprint [GH-167]
- New Stripped down vpc blueprint [GH-170]

- FlexibleAutoScalingGroup blueprint [GH-156]
- Update s3 policies with Remind in-house copies [GH-158]
- Setup correct BucketPolicy for public websites in s3 [GH-159]