Pass version to command when execing
Pass -h/--help in chef exec
Added spec for version and help in exec
Simpler logic for -h in exec
Minor refactor (grouping loops)
Stub out msg in exec_spec
Merge pull request #255 from opscode/jdmundrawala/exec-version

Pass version to command when execing
Implement lockfile overwrite option for Install service
Add basic `update` command to rebuild policyfile.lock.json
Extract UI object tests to shared example group