cmd/swarm: make bzzaccount flag optional and add bzzkeyhex flag (#1531)

* cmd/swarm: don't require bzzaccount flag

* docker: remove setup script because bzzaccount is not required anymore

* cmd/swarm: manage account creation/selection when bzzflag is not defined

* cmd/swarm: no bzzaccount flag tests

* cmd/swarm: use random network ports on tests

* cmd/swarm: fix typo

* cmd/swarm: add --bzzkeyhex flag

* cmd/swarm: use different ipc paths for tests

* readme: update example on how to run swarm

* cmd/swarm: rename getAccount -> getOrCreateAccount

* cmd/swarm: remove unneeded comment

* cmd/swarm: use shorter ipc path for test

cmd/swarm/flags.go

@@ -30,6 +30,11 @@ var (
 		Usage:  "Swarm account key file",
 		EnvVar: SwarmEnvAccount,
 	}
+	SwarmBzzKeyHexFlag = cli.StringFlag{
+		Name:   "bzzkeyhex",
+		Usage:  "BzzAccount key in hex (for testing)",
+		EnvVar: SwarmEnvBzzKeyHex,
+	}
 	SwarmListenAddrFlag = cli.StringFlag{
 		Name:   "httpaddr",
 		Usage:  "Swarm HTTP API listening interface",