clean up report exporting

[teauxfu]

we have a whole dependency on Pandas for one little call in export helper - could be worked around

https://github.com/teauxfu/scalewiz/blob/d0e1d63871fd3a5595cd265f4c44e2a11196a4b6/scalewiz/helpers/export.py#L80-L83

alternatively, we could keep Pandas and try to make better use of it

pandas.normalize_json should help with flattening dicts for the sake of exporting a file that can be easily read by excel

see also #24

[teauxfu]

bump