Use vagrant-vbguest plugin to sync VirtualBox Guest Editions versions

Wiki will need to be updated to reflect this addition

Added script to auto install vagrant-vbguest if it's needed
Don't use common_pypi mirror for devpi.
Merge pull request #978 from edx/feanil/local_pypi

Don't use common_pypi mirror for devpi.
Removing auto install script
Whitespace
Merge pull request #962 from edx/han/Vagrantfile

Use vagrant-vbguest plugin to sync VirtualBox Guest Editions versions
Fix travis.
Merge pull request #980 from edx/feanil/fix_travis

Fix travis.
Allow users to be removed from systems

This will allow us to keep a list of users that are allowed explicitly not allowed to access systems.

user_info:
  - name: someonewholeft
    state: absent
  - name: activeaccount
    type: admin
    github: true

The above settings would ensure that the user named "someonewholeft" is not able to access the system and "activeaccount" is.