WIP: adding 'chef exec'
Revert "WIP: adding 'chef exec'"

This reverts commit 994412ea20bb8a80b221f33d8490fb754bd297c1.
exclude graphviz tags from berks tests
remove mercurial exclusion tag in test_cmd for berks
Merge pull request #23 from opscode/graphviz-tag

exclude graphviz tags from berks tests
Add filtering and explicit omnibus dir to `verify`
Restrict chef tests to unit, use progress formatter
Update help output to include options
Make integration tests opt-in for `verify`
Add smoke tests and run just those by default for 'verify'

Also add a verbosity option, and default to non-verbose output (don't
display the result of successful tests).
REVERT ME: temporarily use mixlib-cli from git