Removed billable property (#111)

Author: changukshin

tp_timesheet/clockify_timesheet.py

@@ -72,7 +72,6 @@ def _post_time_entry(self, date, task, start_time, hour, dry_run):
         time_entry_json = {
             "start": start_timestamp,
             "end": end_timestamp,
-            "billable": True,
             "projectId": project_id,
             "taskId": task_id,
             "tagIds": [self.locale_id],