Merge pull request 'fix export excel en neutralisant les formules comme chaine' (#124) from jmplace/ScoDoc-Lille:fix_formula into master

Reviewed-on: viennet/ScoDoc#124

app/scodoc/sco_excel.py

@@ -224,6 +224,8 @@ class ScoExcelSheet:
         style -- style par défaut (dictionnaire cf. excel_make_style) de la feuille si non spécifié
         """
         cell = WriteOnlyCell(self.ws, value or "")
+        if not (isinstance(value, int) or isinstance(value, float)):
+            cell.data_type = "s"
         # if style is not None and "fill" in style:
         #     toto()
         if style is None: