CLI Integration tests

Run the full suite:

make build
go test -v -p 4 ./cli_test -tags cli_test

-v for verbose, -p 4 to use 4 cores, -tags cli_test a build tag (specified in cli_test.go) to tell go not to ignore the package

NOTE: While the full suite runs in parallel, some of the tests can take up to a minute to complete

NOTE: The tests will use the kvd or kvcli binaries in the build dir. Or in $BUILDDIR if that env var is set.