This is similar to `promtool check-config` and allows one
to validate the alertmanager configuration (as a git presubmit for example).
`govendor fetch github.com/spf13/{cobra,pflag}` was needed to
have support for `Args`.
* Implement alertmanager cli tool 'amtool'
The primary goal of an alertmanager tool is to provide a cli interface
for the prometheus alertmanager.
My vision for this tool has two parts:
- Silence management (query, add, delete)
- Alert management (query, maybe more in future?)
Resolves: #567