Layers and Models update PR

* add residual block
* add test conv and residual block
* modify FFN kwargs

tests/test_layers/test_residual.py

@@ -0,0 +1,26 @@
+from pina.model.layers import ResidualBlock
+import torch
+
+
+def test_constructor():
+
+    res_block = ResidualBlock(input_dim=10,
+                              output_dim=3,
+                              hidden_dim=4)
+    
+    res_block = ResidualBlock(input_dim=10,
+                              output_dim=3,
+                              hidden_dim=4,
+                              spectral_norm=True)
+
+
+def test_forward():
+
+    res_block = ResidualBlock(input_dim=10,
+                              output_dim=3,
+                              hidden_dim=4)
+    
+    x = torch.rand(size=(80, 10))
+    y = res_block(x)
+    assert y.shape[1]==3
+    assert y.shape[0]==x.shape[0]