Cleanup test vector handlers module and prepare for release

[mattsb42-aws]

Description of changes:

• Clean up test vector handlers sub-module
• Add a readme for test vector handlers sub-module
• Set test vector handlers version to 1.0.0 for ready for release

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[karlw00t]

Do each one of the 10 commits here provide benefit? If so, can we break this up into multiple pull requests so we can understand the changes? If not, can this be rebased into a one commit with a clear and concise commit message?

[mattsb42-aws]

@karlw00t They basically fall into five buckets:

1. Renaming the directory
2. tweaks to support testing with older versions
3. fleshing out tests
4. fixing the CLI arguments
5. setting the version

I can split them out if needed, it just didn't seem like any of the changes were significant enough alone to justify five separate PRs.

[karlw00t]

what is awses? Google tell me it's a client for AWS ElasticSeach.

[mattsb42-aws]

Shorthand for "AWS Encryption SDK" ...I forgot that ElasticSearch uses that too...any suggestions for a better shorthand?

[karlw00t]

i'm not willing to fight to hard for it. It's an internal tool, so the name collision shouldn't be too bad.