The controller Docker image included 7 Go binaries (destination,
heartbeat, identity, proxy-injector, public-api, sp-validator, tap),
each roughly 35MB, with similar dependencies.
Change each controller binary into subcommands of a single `controller`
binary, decreasing the controller Docker image size from 315MB to 38MB.
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
Andrew Seigner