Create backbones/__init__.py

src/models/backbones/__init__.py

@@ -0,0 +1,10 @@
+from .wrapper import *
+
+
+#------------------------------------------------------------------------------
+#  Replaceable Backbones
+#------------------------------------------------------------------------------
+
+SUPPORTED_BACKBONES = {
+    'mobilenetv2': MobileNetV2Backbone,
+}