Bees is meant to be run as root only

As bees is meant to be run as root only, move it to /usr/sbin which is
usually not part of normal users path environment.

Makefile

@@ -31,7 +31,7 @@ install: lib src test
 	install -Dm755 bin/bees $(PREFIX)/usr/libexec/bees
 
 install_scripts: ## Install scipts
-	install -Dm755 scripts/beesd $(PREFIX)/usr/bin/beesd
+	install -Dm755 scripts/beesd $(PREFIX)/usr/sbin/beesd
 	install -Dm644 scripts/beesd.conf.sample $(PREFIX)/etc/bees/beesd.conf.sample
 	install -Dm644 scripts/beesd@.service $(PREFIX)/lib/systemd/system/beesd@.service