downgraded openpyxl module to 2.4.9 to fix export in xlsx format

Author: olivierfriard

boris.py

@@ -103,8 +103,8 @@
 import time_budget_functions
 
 
-__version__ = "6.3.1"
-__version_date__ = "2018-05-29"
+__version__ = "6.3.2"
+__version_date__ = "2018-06-14"
 
 if platform.python_version() < "3.5":
     logging.critical("BORIS requires Python 3.5+! You are using v. {}")