add neural network test

tests/test_prediction_techniques/test_neural_networks.py

@@ -0,0 +1,25 @@
+from unittest.mock import patch
+
+import pytest
+
+from prediction_techniques.neural_networks import mlp
+from gamestonk_terminal import load
+
+
+@pytest.fixture
+def stock():
+
+    def load_stock(name, start='2020-06-04'):
+        return load(['-t', name, '-s', start], '', '', '', '')
+
+    return load_stock
+
+
+@pytest.mark.e2e
+def test_mlp(stock):
+
+    with patch('sys.stdout.write') as mock_out:
+        tesla = stock('TSLA')
+        mlp([], tesla[0], tesla[2], tesla[3])
+
+    mock_out.assert_any_call('Predicted share price:')