Nda-tools

* [`nda-tools`] Python2 compatibility fixes and some PEP-8 style changes; fixes [GitHub Issue 9](https://github.com/NDAR/nda-tools/issues/9)
* [`nda-tools`] Addressed issue where configuration file cannot be located on fresh installations.

* [`vtcmd`] Fixed issue with writing debug log files to directory before it is created; fixes [GitHub Issue 12](https://github.com/NDAR/nda-tools/issues/12)
* [`vtcmd`] Removed write mode when opening associated files for upload to S3.
* [`vtcmd`] Update to only fetch multi-part credentials once during resume option in check_submitted_files().
* [`downloadcmd`] Add message regarding transfer limit to download(5TB).
* [`downloadcmd`] Update to use alias when creating local file path to download.
* [`nda-tools`] Update to check version of the client and service.
* [`nda-tools`] Add CHANGELOG.md.

* [`vtcmd`] Update to catch expired token errors and get new credentials so long-running file uploads can complete successfully.
* [`vtcmd`] Update status to "In Progress" in Python client so that this indicates that uploading of files was initiated until it's completed.
* [`nda-tools`] Add debug logging to service calls for the responses/exceptions caught when communicating with services so that improves debugging and issues resolution.

* [`vtcmd`] Decreased batch size for fetching multi-part credentials and updating submission status.

* [`vtcmd`] Update client to check that associated files are readable during associate file step before creating submission package.
* [`vtcmd`] Add support for resuming partially uploaded files when resuming a submission so that it will check which parts are already uploaded, and then only finish uploading the incomplete parts.
* [`vtcmd`] Update to set the size for both datafile and manifest associated files before uploading files so that submission metrics accurately reflect the state of a submission.
* [`nda-tools`] Updated make_config function so that user can use both versions python 2 and python 3.

* [`vtcmd`] Update to handle new message format from services that includes error message details.
* [`vtcmd`] Update to use batch operations for getting multipart upload credentials and for updating status of submission files so that submission of large numbers of files will take less time.