title: lightgbm<=3.3.1: early_stopping() got an unexpected keyword argument 'min_delta'
body: <p>I am dealing with a Regression problem for which I used <code>LGBMRegressor</code>. I also utilize <code>early_stopping</code> as callback in <code>.fit(...)</code> as follows:</p>
  <pre><code>reg = LGBMRegressor(**lgbr_params)
  reg.fit(train_valid[features], 
          train_valid[target], 
          verbose=100,
          eval_set=[(test[features], test[target])], 
                     eval_metric=['rmse', 'mae'],
                     callbacks=[early_stopping(stopping_rounds=10, first_metric_only=False)], )
  </code></pre>
  <p>which works quite fine. However, I would like to consider some sort of &quot;tolerance&quot; in my <code>early_stopping</code> callback function. According to <a href="https://lightgbm.readthedocs.io/en/latest/pythonapi/lightgbm.early_stopping.html" rel="nofollow noreferrer">lightgbm documentation</a>, this is apparently possible using <code>min_delta</code> argument in early stopping callback function.
  When I add this to my code:</p>
  <pre><code>reg = LGBMRegressor(**lgbr_params)
  reg.fit(train_valid[features], 
          train_valid[target], 
          verbose=100,
          eval_set=[(test[features], test[target])], 
                     eval_metric=['rmse', 'mae'],
                     callbacks=[early_stopping(stopping_rounds=10, first_metric_only=False), min_delta=[0.1, 0.1]])
  </code></pre>
  <p>I face with the following error:</p>
  <pre><code>---------------------------------------------------------------------------
  TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-39-834c9eaac9b2&gt; in &lt;module&gt;
        1 reg = LGBMRegressor(**lgbr_params)
        2 reg.fit(train_valid[features], train_valid[target], eval_set=[(test[features], test[target])], eval_metric=['rmse'],
  ----&gt; 3         callbacks=[early_stopping(stopping_rounds=10, first_metric_only=False, min_delta=[1.0])], verbose=100)
  TypeError: early_stopping() got an unexpected keyword argument 'min_delta'
  </code></pre>
  <p>I am using windows, and tried to upgrade the lightbm to solve the issue, but failed.
  Any idea?</p>