* Add github.com/mgechev/revive
* only print the linting issues
* remove redirection to file
* print the revive output
* default formatter to grep easily
* exclude unused-parameter
* plain formatter for excluding only unused-parameter
`godep` by default pulls in all dependencies regardless of build tags. If `tools.go` is in our main package, that can cause unnecessary dependencies to be pulled into others' repos that otherwise don't need them. Moving it to an unused sub-package appears to fix this problem.
Purnesh Dixit
Clément Jean
Doug Fawley
ZhenLian
Jean de Klerk