boolean support for ArgBool
boolean support for ArgBool

not sure why the tests didn't trip on this prior to the refactor :?

replay/metrictank,replay/metrictank,raintank/metrictank,raintank/metrictank,replay/metrictank,replay/metrictank,raintank/raintank-metric,raintank/raintank-metric,raintank/raintank-metric,raintank/metrictank,raintank/metrictank