Make sync-down safe + other fixes/enhancements

• Make sync-down safe (no longer uses the --delete option on rsync)
• Fix some bugs in sync (mostly with proxy version file handling)
• New cli option on run-image -e to specify env variable to set in container
• Fix prompt in bash (castoff wasn't clearing it properly)

CLI Enhancement + bug fixes

Add new cli options:

• ssh-dock
• destroy-dock
• start-dock
• stop-dock

Plus a few bug fixes, most significant is issue with docker not running after instance stop / start.

Support for pre/post script and env expansion

This release provides support for custom scripts to be triggered before and after a build-image command. These two script tags can be applied in the dockerutils.cfg file.

• pre_build_script
• post_build_script

We have also expanded the capabilities of the expansion system to support environment variables as well as some predefined variables.

Fix logic that checks for zsh vs. bash

Merge pull request #14 from resero-labs/bv/fix-logic

Fix logic that checks for zsh

Fix command line prompt updates with dock/castoff.

The command line prompt was not updating consistently in various shells (zsh, bash). This update should fix the problem.

nvidia-smi fix; other minor updates and fixes

Unattended Linux updates were breaking our nvidia configuration. This release fixes that problem along with other minor updates and fixes including 'moniker' functionality.

Bug fix release

We were having issues with the workflow:

1. create-dock
2. stop-instance (aws console)
3. start-instance (aws console)

This release addresses that issue

Remote workstation support

This major release provides the ability for remote workstations (note: currently supported only in aws)

Bug fix release

Fix indentation bug in _version.py.bld generation

Support new features in rappdw/docker-ds

The docker notebook image has been updated to support auto conversion of notebooks to .py and .html files on save for easier human comprehension of version differences.

run-notebook has been updated to support these features.