remove back compatibility files for version 0.2

pina/model/layers/__init__.py

@@ -1,16 +0,0 @@
-"""Old layers module, deprecated in 0.2.0."""
-
-import warnings
-
-from ..block import *
-from ...utils import custom_warning_format
-
-# back-compatibility 0.1
-# Set the custom format for warnings
-warnings.formatwarning = custom_warning_format
-warnings.filterwarnings("always", category=DeprecationWarning)
-warnings.warn(
-    "'pina.model.layers' is deprecated and will be removed "
-    "in future versions. Please use 'pina.model.block' instead.",
-    DeprecationWarning,
-)