Enable auth whoami command

lib/actions/auth.coffee

@@ -25,3 +25,13 @@ exports.signup = ->
 	signupUrl = resin.settings.get('urls.signup')
 	absUrl = url.resolve(resin.settings.get('remoteUrl'), signupUrl)
 	open(absUrl)
+
+exports.whoami = ->
+	resin.auth.whoami (error, username) ->
+		resin.errors.handle(error) if error?
+
+		if not username?
+			error = new Error('Username not found')
+			resin.errors.handle(error)
+
+		resin.log.out(username)

lib/app.coffee

@@ -71,6 +71,11 @@ cli.addCommand
 	description: 'signup to resin.io'
 	action: actions.auth.signup
 
+cli.addCommand
+	command: 'whoami'
+	description: 'get current username'
+	action: actions.auth.whoami
+
 # ---------- App Module ----------
 cli.addResource
 	name: 'app'

lib/resin/auth/auth.coffee

@@ -120,7 +120,7 @@ exports.getToken = (callback) ->
 #
 # @todo Maybe we should post to /logout or something to invalidate the token on the server?
 #
-exports.logout = (callback) ->
+exports.logout = (callback = _.noop) ->
 	async.parallel([
 
 		(callback) ->

lib/resin/auth/auth.spec.coffee

@@ -249,6 +249,9 @@ describe 'Auth:', ->
 					expect(error).to.not.exist
 					done()
 
+			it 'should not throw an error if callback is not passed', ->
+				expect(auth.logout).to.not.throw(Error)
+
 	describe '#parseCredentials', ->
 
 		describe 'given colon separated credentials', ->