title: tflearn throws error when using gpu
body: <p>When I try to use <code>with tf.device('/gpu:0'):</code> in my project it throws the error shown down below. I ve installed tensorflow-gpu.</p>
  
  <p>Code: </p>
  
  <pre><code>def main():
      with tf.device('/gpu:0'):
          model = cnn_model.googlenet(WIDTH, HEIGHT, 3, LR, output=8,model_name=MODEL_NAME)
          model.fit({'input': batch_x}, {'targets': batch_y}, n_epoch=1,snapshot_step=2500, show_metric=True, run_id=MODEL_NAME)
  </code></pre>
  
  <p>cnn_model can be found here: <a href="https://github.com/MrGrimod/gta_self_driving/blob/master/model/cnn_model.py" rel="nofollow noreferrer">https://github.com/MrGrimod/gta_self_driving/blob/master/model/cnn_model.py</a></p>
  
  <p>Error:</p>
  
  <pre><code>WARNING:tensorflow:From 
  C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-        
  packages\tensorflow\python\util\tf_should_use.py:175:         
  initialize_all_variables (from tensorflow.python.ops.variables) is 
  deprecated and will be removed after 2017-03-02.
  Instructions for updating:
  Use `tf.global_variables_initializer` instead.
  hdf5 is not supported on this machine (please install/reinstall h5py for 
  optimal experience)
  curses is not supported on this machine (please install/reinstall curses for 
  an optimal experience)
  Traceback (most recent call last):
  File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
  packages\tensorflow\python\client\session.py", line 1327, in _do_call
  return fn(*args)
  File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
  packages\tensorflow\python\client\session.py", line 1297, in _run_fn
  self._extend_graph()
  File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
  packages\tensorflow\python\client\session.py", line 1358, in _extend_graph
  self._session, graph_def.SerializeToString(), status)
  
  File
  "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\contextlib.py"
  , line 88, in __exit__
  next(self.gen)
   File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
  packages\tensorflow\python\framework\errors_impl.py", line 466, in 
  raise_exception_on_not_ok_status
  pywrap_tensorflow.TF_GetCode(status))
  tensorflow.python.framework.errors_impl.InvalidArgumentError: Node 
  'init_3/NoOp': Unknown input node '^is_training/Assign'
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File "train.py", line 57, in &lt;module&gt;
      main()
    File "train.py", line 26, in main
      model = cnn_model.googlenet(WIDTH, HEIGHT, 3, LR, output=8, 
  model_name=MODEL_NAME)
    File "C:\Users\MrGrimod\Desktop\gta_self_driving\model\cnn_model.py", line 
  147, in googlenet
      max_checkpoints=0, tensorboard_verbose=0,tensorboard_dir='log')
    File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
   packages\tflearn\models\dnn.py", line 65, in __init__
      best_val_accuracy=best_val_accuracy)
    File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
   packages\tflearn\helpers\trainer.py", line 170, in __init__
      self.session.run(init)
    File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
   packages\tensorflow\python\client\session.py", line 895, in run
       run_metadata_ptr)
     File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
   packages\tensorflow\python\client\session.py", line 1124, in _run
       feed_dict_tensor, options, run_metadata)
    File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
    packages\tensorflow\python\client\session.py", line 1321, in _do_run
       options, run_metadata)
     File "C:\Users\MrGrimod\AppData\Local\Programs\Python\Python36\lib\site-
  packages\tensorflow\python\client\session.py", line 1340, in _do_call
      raise type(e)(node_def, op, message)
  tensorflow.python.framework.errors_impl.InvalidArgumentError: Node 
   'init_3/NoOp': Unknown input node '^is_training/Assign'
  2017-09-22 09:59:42.453552: W C:\tf_jenkins\home\workspace\rel-
  win\M\windows\PY\36\tensorflow\core\platform\cpu_feature_guard.cc:45] The 
  TensorFlow library wasn't compiled to use AVX instructions, but these are 
  available on your machine and could speed up CPU computations.
  2017-09-22 09:59:42.453565: W C:\tf_jenkins\home\workspace\rel-
  win\M\windows\PY\36\tensorflow\core\platform\cpu_feature_guard.cc:45] The 
  TensorFlow library wasn't compiled to use AVX2 instructions, but these are 
   available on your machine and could speed up CPU computations.
  </code></pre>