Get lock status by executing directly

Getting the lock status with invoke passes through any options from the
original command which will raise an exception if they are not also
valid for the lock status command.

Fixes https://github.com/mrsked/mrsk/issues/239

test/cli/main_test.rb

@@ -64,7 +64,8 @@ class CliMainTest < CliTestCase
       .with { |*arg| arg[0..1] == [:mkdir, :mrsk_lock] }
       .raises(RuntimeError, "mkdir: cannot create directory ‘mrsk_lock’: File exists")
 
-    Mrsk::Cli::Base.any_instance.expects(:invoke).with("mrsk:cli:lock:status", [])
+    SSHKit::Backend::Abstract.any_instance.expects(:execute)
+      .with(:stat, :mrsk_lock, ">", "/dev/null", "&&", :cat, "mrsk_lock/details", "|", :base64, "-d")
 
     assert_raises(Mrsk::Cli::LockError) do
       run_command("deploy")