made name consistent with linear regression model and const linear model

alphamind/model/linearmodel.py

@@ -69,7 +69,7 @@ class LinearRegression(ModelBase):
         model_desc['desc'] = encoded.decode('ascii')
         model_desc['sklearn_version'] = sklearn_version
         model_desc['trained_time'] = self.trained_time
-        model_desc['coef'] = self.impl.coef_[0].tolist()
+        model_desc['weight'] = self.impl.coef_.tolist()
         return model_desc
 
     def score(self) -> float: