fixing default for THEME_NAME

If THEME_NAME is set to an empty string it will cause a sass error due
to this mako code:

```
% if env.get('THEME_NAME') is not None:
  // import theme's Sass overrides
  @import '${env.get('THEME_NAME')}';
% endif
```
updating comment
Merge pull request #422 from edx/jarv/fix-theme-name

fixing default for THEME_NAME
setting theme name back to an empty string

Setting this to !!null will not work, submitted a bug against ansible so
hopefully this can be resolved.

https://github.com/ansible/ansible/issues/4812

Until then I will fix edx-platform as a work-around to not
use an empty string as an import
fix mode for verified user
Merge pull request #423 from edx/jarv/fix-mode

fix mode for verified user
updating deploy script for jenkins
cert->certs
removing deploy tag from non-deploy task

This causes a problem when you run `--skip-tags deploy`
Refactoring to support new supervisor config.
factoring out common vars into a separate file
factoring out common vars
comment block
use WORKSPACE if it exists for jenkins
General clean-up.
updating provision script to consolidate provisions and deploys
adding commit versions to common var file
extra cd
gh_users is just a list of users, not a dict
fixing names of tasks in launch_ec2