Stub the socket.sleep() function for the SleepWatcher tests

Author: Shados

spec/cmd_spec.moon

@@ -259,8 +259,15 @@ describe "watcher", ->
 
   describe "polling watcher", ->
     before_each ->
+      -- Stub sleep(); it's not actually called during the testing but needs to
+      -- be there for the import in SleepWatcher.new()
+      package.loaded.socket =
+        sleep: () -> nil
       test_watcher = watchers.SleepWatcher output_to, input_paths, prefix_map
 
+    after_each ->
+      package.loaded.socket = nil
+
     describe "process_file_time", ->
       local test_process
       before_each ->