Implemented basic client config for auth

src/commands/login.cr

@@ -0,0 +1,29 @@
+module Faaso
+  module Commands
+    struct Login
+      def run(options) : Int32
+        server = Faaso.server
+        Log.info { "Enter password for #{server}" }
+        if STDIN.tty?
+          password = (STDIN.noecho &.gets.try &.chomp).to_s
+        else
+          password = STDIN.gets.to_s
+        end
+        # Testing with auth/ which is guaranteed locked
+        Crest.get(
+          "#{server}auth/", \
+             user: "admin", password: password).body
+        # If we got here the password is ok
+        CONFIG.hosts[server] = {"admin", password}
+        Config.save
+        0
+      rescue ex : Crest::Unauthorized
+        Log.error { "Wrong password" }
+        1
+      rescue ex : Socket::ConnectError
+        Log.error { "Connection refused" }
+        1
+      end
+    end
+  end
+end