Add first DL_calculation.py test and rename files.

Adds a test for the `run_pelicun` function coming from the first
building assessment from R2D's current Example 1.

pelicun/base.py

@@ -441,7 +441,7 @@ def emit_warnings(self):
         """
         for message in self.warning_stack:
             if message not in self.emitted:
-                warnings.warn(message, PelicunWarning, stacklevel=2)
+                warnings.warn(message, PelicunWarning)
                 if self.warning_file is not None:
                     with open(self.warning_file, 'a', encoding='utf-8') as f:
                         f.write(

pelicun/model/loss_model.py

@@ -1250,6 +1250,15 @@ def load_sample(self, filepath):
         self.sample = file_io.load_data(
             filepath, self._asmnt.unit_conversion_factors, log=self._asmnt.log
         )
+        self.sample.columns.names = [
+            'dv',
+            'loss',
+            'dmg',
+            'loc',
+            'dir',
+            'uid',
+            'block',
+        ]
 
         self.log.msg('Loss sample successfully loaded.', prepend_timestamp=False)