[Makefile] Add default target allinone (clean/vendor/build)

Makefile

@@ -68,6 +68,9 @@ OPENVPN_BIN = "$(HOME)/openvpn_build/sbin/$(shell grep OPENVPN branding/thirdpar
 # go build
 #########################################################################
 
+.PHONY: allinone
+allinone: clean vendor build
+
 install_go:
 	# the version of go in bionic is too old. let's get something newer from a ppa.
 	@sudo apt install software-properties-common