Update 0.13.x release branch for 0.13.10

This MR merges the changes from the following MRs onto the release/0.13.x branch to finalise the 0.13.10 release:

• !722 (merged)
• !725 (merged)

pesummary/core/file/meta_file.py

@@ -5,7 +5,8 @@ import os
 import numpy as np
 import json
 import copy
-
+from getpass import getuser
+import pandas as pd
 import pesummary
 from pesummary import __version__
 from pesummary.core.inputs import PostProcessing
@@ -47,6 +48,8 @@ def recursively_save_dictionary_to_hdf5_file(
         current_path = []
 
     for k, v in dictionary.items():
+        if isinstance(v, pd.DataFrame):
+            v = v.to_dict(orient="list")
         if isinstance(v, dict):
             if k not in f["/" + "/".join(current_path)].keys():
                 f["/".join(current_path)].create_group(k)